文章
Dummer. ゛☀
2017年09月17日
The two most destructive species of cankerworms (a kind of inchworm) in the St. Louis area are the fall cankerworm and the spring cankerworm, both of which feed in the spring. They attack many different species of trees and shrubs.
Symptoms and Diagnosis
Leaves are chewed. Complete defoliation and crop loss may occur; or after repeated damage, less and less fruit is produced until little, if any, fruit matures. Damage is first evident in the early spring or summer after trees have fully leafed out. This is about the time that larvae of both species emerge and begin to feed.
Life Cycle
Cankerworms are small caterpillars, only getting up to an inch long. Adult males are small, gray moths with a wingspan reaching only 1 inch long. The females of both species are wingless.
FALL CANKERWORM: The adult fall cankerworm, Alsophila pometaria, emerges from the ground in late November or early December. The wingless adult females climb up the trunk of the host tree and lay barrel-shaped eggs in masses on twigs and branches. The eggs hatch and larvae begin feeding about the same time leaves begin to emerge. The larvae drop down and dangle on silken threads until swept away by a breeze. The ballooning larvae may travel from plant to plant until a suitable host plant is found. The larvae feed for about a month before they fall to the ground to pupate. The worms have brown backs with white stripes running lengthwise down their backs. The fall cankerworm has three sets of prolegs with the foremost proleg severely stunted. This distinguishes it from the spring cankerworm that has only two pairs of prolegs.
SPRING CANKERWORM: The adult spring cankerworm, Paleacrita vernata, emerges in late February or early March. The wingless adult females climb up the trunk of the tree and lay barrel-shaped eggs in cracks in the bark and underneath the bark and bud scales. Yellow-striped green worms hatch at the same time as fall cankerworm larvae and follow the same general feeding pattern. They too drop to the ground where the larvae overwinter in a protective cell. Spring cankerworm larvae have only two pairs of prolegs.
Integrated Pest Management Strategies
1. Sticky barriers may be banded around tree trunks. Apply a band of a sticky material, such as Tanglefoot, around the trunks of trees in October. The sticky material will trap the wingless females of the fall cankerworm moths as they crawl up the tree trunk to lay eggs in late November or early December. Renew the traps in February to trap the emerging female adults of the spring cankerworm that climb the trunk to lay eggs in late February or early March.
2. Prevent larvae from emerging. In the spring apply a horticultural oil spray on the tree before the larvae hatch, about the time trees just begin to leaf out in the spring.
3. Spray Bt (Bacillus thuringiensis) or Sevin after leaves are fully expanded and flowering is finished. Repeat this application two more times, at 14-day intervals. Sevin is very toxic to bees, hence spraying should be delayed until after flowering to limit damage to these beneficial insects.
Symptoms and Diagnosis
Leaves are chewed. Complete defoliation and crop loss may occur; or after repeated damage, less and less fruit is produced until little, if any, fruit matures. Damage is first evident in the early spring or summer after trees have fully leafed out. This is about the time that larvae of both species emerge and begin to feed.
Life Cycle
Cankerworms are small caterpillars, only getting up to an inch long. Adult males are small, gray moths with a wingspan reaching only 1 inch long. The females of both species are wingless.
FALL CANKERWORM: The adult fall cankerworm, Alsophila pometaria, emerges from the ground in late November or early December. The wingless adult females climb up the trunk of the host tree and lay barrel-shaped eggs in masses on twigs and branches. The eggs hatch and larvae begin feeding about the same time leaves begin to emerge. The larvae drop down and dangle on silken threads until swept away by a breeze. The ballooning larvae may travel from plant to plant until a suitable host plant is found. The larvae feed for about a month before they fall to the ground to pupate. The worms have brown backs with white stripes running lengthwise down their backs. The fall cankerworm has three sets of prolegs with the foremost proleg severely stunted. This distinguishes it from the spring cankerworm that has only two pairs of prolegs.
SPRING CANKERWORM: The adult spring cankerworm, Paleacrita vernata, emerges in late February or early March. The wingless adult females climb up the trunk of the tree and lay barrel-shaped eggs in cracks in the bark and underneath the bark and bud scales. Yellow-striped green worms hatch at the same time as fall cankerworm larvae and follow the same general feeding pattern. They too drop to the ground where the larvae overwinter in a protective cell. Spring cankerworm larvae have only two pairs of prolegs.
Integrated Pest Management Strategies
1. Sticky barriers may be banded around tree trunks. Apply a band of a sticky material, such as Tanglefoot, around the trunks of trees in October. The sticky material will trap the wingless females of the fall cankerworm moths as they crawl up the tree trunk to lay eggs in late November or early December. Renew the traps in February to trap the emerging female adults of the spring cankerworm that climb the trunk to lay eggs in late February or early March.
2. Prevent larvae from emerging. In the spring apply a horticultural oil spray on the tree before the larvae hatch, about the time trees just begin to leaf out in the spring.
3. Spray Bt (Bacillus thuringiensis) or Sevin after leaves are fully expanded and flowering is finished. Repeat this application two more times, at 14-day intervals. Sevin is very toxic to bees, hence spraying should be delayed until after flowering to limit damage to these beneficial insects.
0
0
文章
Dummer. ゛☀
2017年09月17日
The brown marmorated stink bug (Halyomorpha halys) is an Asian species that was introduced into Allentown, Pennsylvania around 1996 from China or Japan. In 2015 it was found in 42 states including Missouri. Its range is increasing in Missouri and is projected to be a major pest of vegetable and fruit crops including apples, peaches and blackberries, as well as, a nuisance in homes where it can overwinter. However, it will not reproduce inside homes or cause structural damage. It can be confused with other stink bugs, notably the brown stink bug, which is smaller and less destructive.
Symptoms and Diagnosis
Brown marmorated stink bugs (BMSB), like other stink bugs, feed by inserting their mouth parts into the leaves, flowers, buds, fruits, and seeds of host plants and sucking plant sap. Large infestations of stink bugs may cause plants, especially small plants and young tender growth, to wilt, become stunted and misshapen, or die. Other damage includes yellow or white blotches on leaves; misshapen or aborted fruits, seeds, and buds; calluses, blemishes or depressions; and black pits on nuts. Tomatoes exhibit a condition called cloudy spot (pale yellow spots and a white pithy area just under the skin at the puncture site). Peaches and other fruits may develop scarring and dimpling resulting in cat-facing or a pitted appearance. The seeds in soybean pods may be deformed, small, discolored, or shriveled.
Life Cycle
Adult brown marmorated stink bugs are about ½ inch long and have the characteristic “shield” shape of stink bugs. They are mottled brownish grey in color with a white or pale gray underside. The antennae and legs have light bands. The edges of the abdomen that extend beyond the sides of the wings have brown and white bands. The native brown stink bug is smaller and has a light green underside. It lacks the bands on the antennae and legs.
Adults overwinter outdoors and in buildings and emerge in late March through April when they mate and lay eggs on the underside of leaves May through August. The eggs (about 1/16 inch in size) are light yellow, yellow-red or green and are laid up against each other in clusters of 20 to 30 eggs. The eggs hatch in 1-3 weeks into brightly colored red and black nymphs with banded legs and antennae. They have a “tick-like” appearance. The nymphs begin feeding and progress through 5 instars to adulthood. By the second instar the banded abdominal extension has clearly begun to develop. In northern areas there may be only one generation a year but in warmer, southern states there may be up to three generations a year. In Missouri, there may be two generations a year.
In late September into mid-October adults seek protected areas for overwintering. They can gain access into homes through cracks and opening around windows, doors, siding, fascia boards, chimneys, attics or window air conditioners where they overwinter in walls and other locations. In spring, they can be found in interior spaces as they look for ways to reach the outdoor.
Integrated Pest Management Strategies
There are no easy controls for the brown marmorated stink bug, but here are some suggestions for management.
Outdoors
1. Sanitation. Control weeds in susceptible crops and in areas adjacent to gardens to decrease breeding and overwintering habitat. It is important to remove weeds early in the growing season before stink bug populations increase or the loss of habitat may force pests to move into the garden.
2. Collect insects. Hand pick and destroy eggs and bugs. When hand picking, use gloves as dermatitis at the point of contact can occur. Some individuals are also allergic to the smell of stink bugs. Indoors, use a shop vacuum to vacuum up the overwintered adults.
3. Use natural controls. Although there are currently no known natural predators, it is always wise to encourage other natural predators such as parasitic wasps and flies by growing small-flowered plants. The unpleasant odor produced by stink bugs deters many predators but several bird species do consume these pests.
4. Use insecticides. Control with pesticides is short-lived and difficult. Also, resistance to some pesticides has already been observed. If damage is severe and there is a need to save a crop, you can try sabadilla, pyrethrin or permethrin (Eight). Check label directions for suitability with your crop before using.
Symptoms and Diagnosis
Brown marmorated stink bugs (BMSB), like other stink bugs, feed by inserting their mouth parts into the leaves, flowers, buds, fruits, and seeds of host plants and sucking plant sap. Large infestations of stink bugs may cause plants, especially small plants and young tender growth, to wilt, become stunted and misshapen, or die. Other damage includes yellow or white blotches on leaves; misshapen or aborted fruits, seeds, and buds; calluses, blemishes or depressions; and black pits on nuts. Tomatoes exhibit a condition called cloudy spot (pale yellow spots and a white pithy area just under the skin at the puncture site). Peaches and other fruits may develop scarring and dimpling resulting in cat-facing or a pitted appearance. The seeds in soybean pods may be deformed, small, discolored, or shriveled.
Life Cycle
Adult brown marmorated stink bugs are about ½ inch long and have the characteristic “shield” shape of stink bugs. They are mottled brownish grey in color with a white or pale gray underside. The antennae and legs have light bands. The edges of the abdomen that extend beyond the sides of the wings have brown and white bands. The native brown stink bug is smaller and has a light green underside. It lacks the bands on the antennae and legs.
Adults overwinter outdoors and in buildings and emerge in late March through April when they mate and lay eggs on the underside of leaves May through August. The eggs (about 1/16 inch in size) are light yellow, yellow-red or green and are laid up against each other in clusters of 20 to 30 eggs. The eggs hatch in 1-3 weeks into brightly colored red and black nymphs with banded legs and antennae. They have a “tick-like” appearance. The nymphs begin feeding and progress through 5 instars to adulthood. By the second instar the banded abdominal extension has clearly begun to develop. In northern areas there may be only one generation a year but in warmer, southern states there may be up to three generations a year. In Missouri, there may be two generations a year.
In late September into mid-October adults seek protected areas for overwintering. They can gain access into homes through cracks and opening around windows, doors, siding, fascia boards, chimneys, attics or window air conditioners where they overwinter in walls and other locations. In spring, they can be found in interior spaces as they look for ways to reach the outdoor.
Integrated Pest Management Strategies
There are no easy controls for the brown marmorated stink bug, but here are some suggestions for management.
Outdoors
1. Sanitation. Control weeds in susceptible crops and in areas adjacent to gardens to decrease breeding and overwintering habitat. It is important to remove weeds early in the growing season before stink bug populations increase or the loss of habitat may force pests to move into the garden.
2. Collect insects. Hand pick and destroy eggs and bugs. When hand picking, use gloves as dermatitis at the point of contact can occur. Some individuals are also allergic to the smell of stink bugs. Indoors, use a shop vacuum to vacuum up the overwintered adults.
3. Use natural controls. Although there are currently no known natural predators, it is always wise to encourage other natural predators such as parasitic wasps and flies by growing small-flowered plants. The unpleasant odor produced by stink bugs deters many predators but several bird species do consume these pests.
4. Use insecticides. Control with pesticides is short-lived and difficult. Also, resistance to some pesticides has already been observed. If damage is severe and there is a need to save a crop, you can try sabadilla, pyrethrin or permethrin (Eight). Check label directions for suitability with your crop before using.
0
0
文章
Dummer. ゛☀
2017年09月17日
The fungus, Armillaria mellea, occurs sporadically in this region and has been reported to infect over 25 species of ornamental trees and shrubs. The most distinctive sign of Armillaria infection is the honeycolored mushroom that grows from the roots and base of plants. The fungus is especially prevalent on oak but also affects many different kinds of fruit and nut trees, ornamentals, and herbaceous plantings. It is often referred to as oak root rot fungus because it is commonly found on oaks or in areas where oaks trees once were grown, such as cleared forest land.
Symptoms and Diagnosis
The symptoms of Armillaria are similar to those of other root disorders; height growth is reduced, foliage is sparse, and leaves that remain on plants are stunted and yellow. An abnormal flow of sap may be visible on the root collar. When soil is removed from the base of the trunk, black, root-like strands are visible and attached to larger roots. White to dark, fan-shaped mats of fungal strands develop between the bark and wood in infected root and trunk tissues. The most positive sign of infection is the production of clusters of honey-colored mushrooms at the base of the tree near the soil line. The mushrooms may have stalks 4 to 6 inches high with caps 1 inch high and 2 to 4 inches wide.
Life Cycle
Armillaria is found in the soil sporadically throughout the Midwest. The fungus spreads primarily by root-to-root contact or by root-like fungal strands. Root-like fungal strands grow through the soil and adhere to the host roots or root collar that it encounters. Successfully attacked trees do not die until infections girdle the base of the tree. On healthy, vigorous trees, Armillaria is not lethal but if present, it may begin to grow when the tree dies of other causes. Young trees are more likely to be killed by Armillaria. Trees that are 15–20 years old are more tolerant to attack.
Integrated Pest Management Strategies
1. Remove and destroy infected material. Remove as much of the stump as possible. Sterilize tools with a solution of 1–part bleach with 9–parts water after use.
2. Provide adequate moisture in a well-drained soil to maintain vigor and resistance to infection. Plants suffering from drought are extremely susceptible to infection. Fertilize trees appropriately in late winter or early spring.
3. No effective chemical controls are known. Plants reported by Auburn University to be resistant to Armillaria root rot include ginkgo, tulip tree, ash, bald cypress, cherry, Chinese elm, Chinese pistache, crabapple, cryptomeria, dawn redwood, eucalyptus, hackberry, holly, incense cedar, Leyland cypress, maidenhair tree, maple, privet, smoke tree, sweetgum, tree-ofheaven, white fir, and wisteria. These should be considered for replacement of diseased trees. New soil should be used to amend the planting site. All diseased material and associated roots, as much as possible, should be excavated before replanting.
Symptoms and Diagnosis
The symptoms of Armillaria are similar to those of other root disorders; height growth is reduced, foliage is sparse, and leaves that remain on plants are stunted and yellow. An abnormal flow of sap may be visible on the root collar. When soil is removed from the base of the trunk, black, root-like strands are visible and attached to larger roots. White to dark, fan-shaped mats of fungal strands develop between the bark and wood in infected root and trunk tissues. The most positive sign of infection is the production of clusters of honey-colored mushrooms at the base of the tree near the soil line. The mushrooms may have stalks 4 to 6 inches high with caps 1 inch high and 2 to 4 inches wide.
Life Cycle
Armillaria is found in the soil sporadically throughout the Midwest. The fungus spreads primarily by root-to-root contact or by root-like fungal strands. Root-like fungal strands grow through the soil and adhere to the host roots or root collar that it encounters. Successfully attacked trees do not die until infections girdle the base of the tree. On healthy, vigorous trees, Armillaria is not lethal but if present, it may begin to grow when the tree dies of other causes. Young trees are more likely to be killed by Armillaria. Trees that are 15–20 years old are more tolerant to attack.
Integrated Pest Management Strategies
1. Remove and destroy infected material. Remove as much of the stump as possible. Sterilize tools with a solution of 1–part bleach with 9–parts water after use.
2. Provide adequate moisture in a well-drained soil to maintain vigor and resistance to infection. Plants suffering from drought are extremely susceptible to infection. Fertilize trees appropriately in late winter or early spring.
3. No effective chemical controls are known. Plants reported by Auburn University to be resistant to Armillaria root rot include ginkgo, tulip tree, ash, bald cypress, cherry, Chinese elm, Chinese pistache, crabapple, cryptomeria, dawn redwood, eucalyptus, hackberry, holly, incense cedar, Leyland cypress, maidenhair tree, maple, privet, smoke tree, sweetgum, tree-ofheaven, white fir, and wisteria. These should be considered for replacement of diseased trees. New soil should be used to amend the planting site. All diseased material and associated roots, as much as possible, should be excavated before replanting.
0
0
文章
Dummer. ゛☀
2017年09月17日
There are over 1200 known species of whiteflies, most of which feed on only one or a few species of plants each. Some are pests on valuable crops such as the sweet potato whitefly (Bemisia tabaci). Others, like the greenhouse whitefly (Trialeurodes vaporariorum), feed on a broad range of herbaceous plants both inside the greenhouse and outside in the garden. Some of the host plants that the greenhouse whitefly attacks are the tomato, fuchsia, lantana, and coleus.
The silverleaf whitefly (Bemisia argentifolii) has been found on as many as 500 hosts such as canna lilies, bearded iris, crepe myrtle, lantana, petunia, and rose.
Whiteflies are one of the most difficult insect pests to control. They are not true flies but are more closely related to aphids, mealybugs, and scale, which are also sap-sucking insects. In some parts of the country, some species of whitefly can transmit several plant viruses.
Symptoms and Diagnosis
Identification of the whitefly is easy as a white cloud of insects rise from foliage when disturbed. The adults are about 1/16 to 1/10 inch in length, wedgeshaped, and appear powdery. Infested leaves may show little if any symptoms or may be mottled and yellow. Leaves will also become coated with a sticky substance called honeydew, which is secreted by feeding whitefly nymphs and adults. A black, sooty mold may sometimes grow on the honeydew. Sooty mold does not damage the leaf. The feeding, however, removes nutrients from the plant, which results in stunting, poor growth, defoliation, reduced yields, and sometimes death. On certain plants the silverleaf whitefly causes specific damage symptoms such as silvering of leaves on squash, irregular ripening in tomato, whitestalk in broccoli and cauliflower, light root in carrots, and white stem in poinsettia.
Life Cycle
The whitefly spends its winters in weeds and ornamental plants, migrating to crops and gardens in spring and summer. Once temperatures warm up in the summer, populations can build rapidly with the highest populations probably occurring in late summer. They lay their tiny eggs on the undersides of leaves. Adult females usually lay between 200 to 400 eggs. Sometimes the eggs are deposited in a circular pattern (not true in all species) in groups of 30 to 40 as the female will often keep her mouth part in the plant to feed while moving in a circle to deposit eggs. Within about a week the eggs hatch into flattened nymphs, called crawlers that wander about the plant. Soon, they insert their mouth part and begin to feed. The first stage has legs and antennae, but these are lost after the first molt and the flattened, oval-shaped larvae stay fixed at one feeding site. The last part of the fourth instar is the pupa. Adults emerge from the pupa through a Tshaped slit and soon mate and reproduce. The adults live about one month. Within a population, all life stages are present and generations often overlap.
Integrated Pest Management Strategies
1. Inspection. Inspect all new plants planted in the garden for whiteflies. Inspect regularly and remove by hand older leaves that are heavily infested with whiteflies in a non-mobile nymphal stage.
2. Biological control. Whiteflies have many natural enemies in the garden setting including spiders, lady beetles, and lacewings. However, these predators are not effective if there is a frequent use of insecticides.
3. Mechanical control. The use of traps can be very helpful in controlling light infestations. Make yellow sticky traps about 12 x 6 inches and coat them with a sticky substance such as Tanglefoot, petroleum jelly, or heavy grade motor oil. Hang the traps vertically near the affected plants. The adults are attracted to yellow. Traps are also commercially available. Use one trap per plant.
4. Chemical control. Whiteflies have developed resistance to some chemicals. Because of this resistance, a certain product may work well in one area but not in another. Resistance may be delayed by alternating the types of chemicals used. In addition, the egg and non-feeding pupa stages are generally not as susceptible to insecticides as are the adults and nymphs. Consequently, eradication of a whitefly population usually requires four to five applications of a registered insecticide at five to seven day intervals. Be sure the applications are made to the lower leaf surface, and apply as soon as whiteflies are detected. Do not wait until populations become severe.
Before using any insecticide for whitefly control, make sure that the site and target plant are both listed on the label. Follow label directions carefully.
5. Chemicals. Some of the over-the-counter chemicals which could be used are malathion, imidacloprid, permethrin, or pyrethrins. Insecticidal soap, petroleum oil, and insect growth regulators can also be effective.
The silverleaf whitefly (Bemisia argentifolii) has been found on as many as 500 hosts such as canna lilies, bearded iris, crepe myrtle, lantana, petunia, and rose.
Whiteflies are one of the most difficult insect pests to control. They are not true flies but are more closely related to aphids, mealybugs, and scale, which are also sap-sucking insects. In some parts of the country, some species of whitefly can transmit several plant viruses.
Symptoms and Diagnosis
Identification of the whitefly is easy as a white cloud of insects rise from foliage when disturbed. The adults are about 1/16 to 1/10 inch in length, wedgeshaped, and appear powdery. Infested leaves may show little if any symptoms or may be mottled and yellow. Leaves will also become coated with a sticky substance called honeydew, which is secreted by feeding whitefly nymphs and adults. A black, sooty mold may sometimes grow on the honeydew. Sooty mold does not damage the leaf. The feeding, however, removes nutrients from the plant, which results in stunting, poor growth, defoliation, reduced yields, and sometimes death. On certain plants the silverleaf whitefly causes specific damage symptoms such as silvering of leaves on squash, irregular ripening in tomato, whitestalk in broccoli and cauliflower, light root in carrots, and white stem in poinsettia.
Life Cycle
The whitefly spends its winters in weeds and ornamental plants, migrating to crops and gardens in spring and summer. Once temperatures warm up in the summer, populations can build rapidly with the highest populations probably occurring in late summer. They lay their tiny eggs on the undersides of leaves. Adult females usually lay between 200 to 400 eggs. Sometimes the eggs are deposited in a circular pattern (not true in all species) in groups of 30 to 40 as the female will often keep her mouth part in the plant to feed while moving in a circle to deposit eggs. Within about a week the eggs hatch into flattened nymphs, called crawlers that wander about the plant. Soon, they insert their mouth part and begin to feed. The first stage has legs and antennae, but these are lost after the first molt and the flattened, oval-shaped larvae stay fixed at one feeding site. The last part of the fourth instar is the pupa. Adults emerge from the pupa through a Tshaped slit and soon mate and reproduce. The adults live about one month. Within a population, all life stages are present and generations often overlap.
Integrated Pest Management Strategies
1. Inspection. Inspect all new plants planted in the garden for whiteflies. Inspect regularly and remove by hand older leaves that are heavily infested with whiteflies in a non-mobile nymphal stage.
2. Biological control. Whiteflies have many natural enemies in the garden setting including spiders, lady beetles, and lacewings. However, these predators are not effective if there is a frequent use of insecticides.
3. Mechanical control. The use of traps can be very helpful in controlling light infestations. Make yellow sticky traps about 12 x 6 inches and coat them with a sticky substance such as Tanglefoot, petroleum jelly, or heavy grade motor oil. Hang the traps vertically near the affected plants. The adults are attracted to yellow. Traps are also commercially available. Use one trap per plant.
4. Chemical control. Whiteflies have developed resistance to some chemicals. Because of this resistance, a certain product may work well in one area but not in another. Resistance may be delayed by alternating the types of chemicals used. In addition, the egg and non-feeding pupa stages are generally not as susceptible to insecticides as are the adults and nymphs. Consequently, eradication of a whitefly population usually requires four to five applications of a registered insecticide at five to seven day intervals. Be sure the applications are made to the lower leaf surface, and apply as soon as whiteflies are detected. Do not wait until populations become severe.
Before using any insecticide for whitefly control, make sure that the site and target plant are both listed on the label. Follow label directions carefully.
5. Chemicals. Some of the over-the-counter chemicals which could be used are malathion, imidacloprid, permethrin, or pyrethrins. Insecticidal soap, petroleum oil, and insect growth regulators can also be effective.
0
0
文章
Dummer. ゛☀
2017年09月17日
Mealybugs get their common name from white waxy secretions that cover their bodies. They are in the order Homoptera, which includes scales, whiteflies, and aphids, some species of which also cover their bodies with white waxy secretions, making field identification confusing. In warmer climates, mealybugs are serious pests on many citrus and ornamental plants. In this area, a wide variety of indoor and tropical plants summered outdoors or maintained in greenhouses can be attacked, as can many outdoor woody trees and shrubs, perennials, and summer annuals (e.g. begonia and coleus).
Some mealybug species can overwinter as nymphs and eggs. However, outside resurgences in the spring often come from introduction of mealybuginfested plants, with young nymphs from the infested plant colonizing nearby plants. Ants may also transport mealybugs from one plant to another.
Symptoms and Diagnosis
The typical female mealybug is 1/16 to 1/8 inch long with a white, waxy, oval body and functional legs. Some species are up to1/4 inch long. Males are much smaller, usually winged, and seldom seen.
Mealybugs infest all plant parts; feeder roots, root crowns, stems, twigs, leaves, flowers, and fruit. Here, mealybug infestations usually involve leaves (mostly undersides), stems, branches, and joints. They pierce and suck sap, excreting a sticky honeydew over leaves and stems that provides an excellent growth medium for a sooty-colored mold, giving the plant a dirty, sooty appearance. Ants are likely to be found feeding on the honeydew.
Heavily infested plants will experience irregular or no growth, yellowed leaves, and significant leaf drop. Left untreated, plants can die.
Life Cycle
Most species are egg layers, though some, especially under greenhouse-like conditions, give live birth. Normally, females lay about 500 eggs in a cottony mass. Hatching in 1 to 2 weeks, nymphs resemble adult females, but male and females then develop differently. Female nymphs increase in size with each molt, reaching adulthood in about a month. In contrast, male mealybugs go through two or so molts and then enter a pupal state in a flimsy cocoon before hatching as a tiny, fly-like, twowinged adult, incapable of feeding and soon to die.
Outdoors, two generations a year are common. Eight generations a year are possible in optimal greenhouse-like conditions. Several developmental stages can usually be found simultaneously.
Integrated Pest Management Strategies
1. Prevent new infestations. Examine, quarantine for 2 or 3 weeks, and treat as necessary (see below) all new plants before placing them near mealybug-free plants. Examine all plants frequently for pests.
2. Conserve natural enemies. Predatory insects, such as lacewings, syrphid flies, ladybugs, and several small parasitic wasps, prey on outdoor mealybugs and can often keep their population within bounds. An introduced beetle, Cryptolaemus montrouzieri, the mealybug destroyer, is available commercially for release in greenhouses. Avoid unnecessary insecticide use to minimize damage to these beneficial insects.
3. Remove mealybugs manually. Depending on host plant size and scope of infestation, remove mealybugs with alcohol-dipped cotton swabs or physically knock them off plants with a forceful water spray and repeat as necessary. While unlikely to eliminate mealybugs, this approach can often keep the infestation within tolerable limits and will have no negative impact on beneficial insects.
4. Control ants. Ants are known to transport mealybugs from one plant to another, so physical barriers or chemical controls that do not adversely impact beneficial insects can be part of a prevention and control program.
5. Use insecticidal soap or superior horticulture oil sprays. If above methods fail to reduce mealybug populations to acceptable levels, use insecticidal soap sprays or superior horticultural oil spray following label directions carefully to avoid damage to sensitive plants and beneficial insects. If possible, treat when crawlers are present. Mealybugs hide under leaves and in crotches, so be sure spraying is thorough. Repeat application as necessary in accordance with label instructions.
6. Use chemical insecticides. Acephate (Orthene), bifenthrin, and pyrethrins are effective against mealybugs. Follow label directions carefully.
Some mealybug species can overwinter as nymphs and eggs. However, outside resurgences in the spring often come from introduction of mealybuginfested plants, with young nymphs from the infested plant colonizing nearby plants. Ants may also transport mealybugs from one plant to another.
Symptoms and Diagnosis
The typical female mealybug is 1/16 to 1/8 inch long with a white, waxy, oval body and functional legs. Some species are up to1/4 inch long. Males are much smaller, usually winged, and seldom seen.
Mealybugs infest all plant parts; feeder roots, root crowns, stems, twigs, leaves, flowers, and fruit. Here, mealybug infestations usually involve leaves (mostly undersides), stems, branches, and joints. They pierce and suck sap, excreting a sticky honeydew over leaves and stems that provides an excellent growth medium for a sooty-colored mold, giving the plant a dirty, sooty appearance. Ants are likely to be found feeding on the honeydew.
Heavily infested plants will experience irregular or no growth, yellowed leaves, and significant leaf drop. Left untreated, plants can die.
Life Cycle
Most species are egg layers, though some, especially under greenhouse-like conditions, give live birth. Normally, females lay about 500 eggs in a cottony mass. Hatching in 1 to 2 weeks, nymphs resemble adult females, but male and females then develop differently. Female nymphs increase in size with each molt, reaching adulthood in about a month. In contrast, male mealybugs go through two or so molts and then enter a pupal state in a flimsy cocoon before hatching as a tiny, fly-like, twowinged adult, incapable of feeding and soon to die.
Outdoors, two generations a year are common. Eight generations a year are possible in optimal greenhouse-like conditions. Several developmental stages can usually be found simultaneously.
Integrated Pest Management Strategies
1. Prevent new infestations. Examine, quarantine for 2 or 3 weeks, and treat as necessary (see below) all new plants before placing them near mealybug-free plants. Examine all plants frequently for pests.
2. Conserve natural enemies. Predatory insects, such as lacewings, syrphid flies, ladybugs, and several small parasitic wasps, prey on outdoor mealybugs and can often keep their population within bounds. An introduced beetle, Cryptolaemus montrouzieri, the mealybug destroyer, is available commercially for release in greenhouses. Avoid unnecessary insecticide use to minimize damage to these beneficial insects.
3. Remove mealybugs manually. Depending on host plant size and scope of infestation, remove mealybugs with alcohol-dipped cotton swabs or physically knock them off plants with a forceful water spray and repeat as necessary. While unlikely to eliminate mealybugs, this approach can often keep the infestation within tolerable limits and will have no negative impact on beneficial insects.
4. Control ants. Ants are known to transport mealybugs from one plant to another, so physical barriers or chemical controls that do not adversely impact beneficial insects can be part of a prevention and control program.
5. Use insecticidal soap or superior horticulture oil sprays. If above methods fail to reduce mealybug populations to acceptable levels, use insecticidal soap sprays or superior horticultural oil spray following label directions carefully to avoid damage to sensitive plants and beneficial insects. If possible, treat when crawlers are present. Mealybugs hide under leaves and in crotches, so be sure spraying is thorough. Repeat application as necessary in accordance with label instructions.
6. Use chemical insecticides. Acephate (Orthene), bifenthrin, and pyrethrins are effective against mealybugs. Follow label directions carefully.
0
0
文章
Dummer. ゛☀
2017年09月16日
Numerous species of leafhoppers and planthoppers are found in Missouri, and many of them have a broad host list (for example, the potato leafhopper, Empoasca fabae, has over 100 host plants). They feed on foliage and shoots of many different plant species by piercing the plant cells and sucking out the contents. The damage that results from feeding depends on the host plant and the specific hopper. Only a few species of hoppers transmit pathogens such as those that cause curly top virus and aster yellows. Adult hoppers are excellent short-distance jumpers when disturbed, and they can be pests when found in high numbers.
Symptoms and Diagnosis
Hoppers are agile insects that can move with equal ease either forwards, backwards, or sideways like a crab. The crab-like motion distinguishes hoppers from most other insects. In addition, they can hop to escape danger or to move to another host plant.
Feeding damage from some species causes small white spots (stippling) to appear on the upper leaf surface, usually beginning near the leaf midrib.
Stippled areas can unite into larger whitish blotches on mature leaves. With some plants, feeding damage causes a drying and yellowing (or browning) of leaf margins, and possibly the whole leaf. Some leafhopper species cause curling or stunting of terminal leaves with their feeding. Another sign of feeding is the presence of tiny varnish-like spots of excrement on the underside of leaves. Also, check under leaves for white, papery cast skins that remain from the molting process.
The lacebug is another insect that causes stippling from feeding and leaves dark droplets of varnish-like excrement on the underside of leaves. Distinguishing lacebugs from leafhoppers is easy:
Lacebugs have a lacy pattern on their upper side, they don't jump or run sideways, and they are about half as broad as they are long. Yet another pest that can cause stippling is the spider mite. Check under leaves for the webbing left by spider mites (leafhoppers don't leave webbing).
Life Cycle
Adults of most species of leafhopper range between 1/8 to 1/4 inch long. They are slender and frequently have an angular, pointed head. Coloration depends on species, but generally leafhoppers are shades of green, brown, or yellow and are often mottled. Nymphs (immatures) look similar to the adults except that the nymphs are smaller and don't have wings. Nymphs typically feed on the underside of leaves, where the humidity is higher and they are more protected from predators.
Leafhoppers have several generations each year. Some species migrate south in winter and return north with late spring weather.
Integrated Pest Management Strategies
1. Live with the pests. Because of their mobility and abundance, leafhoppers are not easy to control. However, leafhoppers are seldom present in large enough numbers to seriously injure plants. In addition, leafhoppers have many natural enemies, including lady beetles, lacewings, damsel bugs, and spiders. They are also subject to diseases and parasites that help keep their numbers down under most conditions.
2. Use row covers. Floating row covers or netting can be placed over plants early in summer to exclude leafhoppers. Remove row covers when the plants begin to flower.
3. Monitor with sticky traps. Many leafhoppers are attracted to yellow sticky traps which should be placed close to the foliage of the crop. Populations can be monitored with sticky traps and low populations can be managed using these traps.
4. Apply insecticidal soap. Insecticidal soap can control leafhoppers if applied when the insects are small. The immature leafhoppers are usually found on the underside of leaves so be sure to spray there also.
5. Apply insecticides. Other insecticides available for leafhopper control include botanical pyrethrins, carbaryl (Sevin), malathion, bifenthrin, cyfluthrin, bendiocarb (Turcam, Closure), disulfoton (Disyston), and acephate (Orthene). In general, these are most effective on the immature leafhoppers because they can't escape as well as the adults and are typically more susceptible to chemicals.
Symptoms and Diagnosis
Hoppers are agile insects that can move with equal ease either forwards, backwards, or sideways like a crab. The crab-like motion distinguishes hoppers from most other insects. In addition, they can hop to escape danger or to move to another host plant.
Feeding damage from some species causes small white spots (stippling) to appear on the upper leaf surface, usually beginning near the leaf midrib.
Stippled areas can unite into larger whitish blotches on mature leaves. With some plants, feeding damage causes a drying and yellowing (or browning) of leaf margins, and possibly the whole leaf. Some leafhopper species cause curling or stunting of terminal leaves with their feeding. Another sign of feeding is the presence of tiny varnish-like spots of excrement on the underside of leaves. Also, check under leaves for white, papery cast skins that remain from the molting process.
The lacebug is another insect that causes stippling from feeding and leaves dark droplets of varnish-like excrement on the underside of leaves. Distinguishing lacebugs from leafhoppers is easy:
Lacebugs have a lacy pattern on their upper side, they don't jump or run sideways, and they are about half as broad as they are long. Yet another pest that can cause stippling is the spider mite. Check under leaves for the webbing left by spider mites (leafhoppers don't leave webbing).
Life Cycle
Adults of most species of leafhopper range between 1/8 to 1/4 inch long. They are slender and frequently have an angular, pointed head. Coloration depends on species, but generally leafhoppers are shades of green, brown, or yellow and are often mottled. Nymphs (immatures) look similar to the adults except that the nymphs are smaller and don't have wings. Nymphs typically feed on the underside of leaves, where the humidity is higher and they are more protected from predators.
Leafhoppers have several generations each year. Some species migrate south in winter and return north with late spring weather.
Integrated Pest Management Strategies
1. Live with the pests. Because of their mobility and abundance, leafhoppers are not easy to control. However, leafhoppers are seldom present in large enough numbers to seriously injure plants. In addition, leafhoppers have many natural enemies, including lady beetles, lacewings, damsel bugs, and spiders. They are also subject to diseases and parasites that help keep their numbers down under most conditions.
2. Use row covers. Floating row covers or netting can be placed over plants early in summer to exclude leafhoppers. Remove row covers when the plants begin to flower.
3. Monitor with sticky traps. Many leafhoppers are attracted to yellow sticky traps which should be placed close to the foliage of the crop. Populations can be monitored with sticky traps and low populations can be managed using these traps.
4. Apply insecticidal soap. Insecticidal soap can control leafhoppers if applied when the insects are small. The immature leafhoppers are usually found on the underside of leaves so be sure to spray there also.
5. Apply insecticides. Other insecticides available for leafhopper control include botanical pyrethrins, carbaryl (Sevin), malathion, bifenthrin, cyfluthrin, bendiocarb (Turcam, Closure), disulfoton (Disyston), and acephate (Orthene). In general, these are most effective on the immature leafhoppers because they can't escape as well as the adults and are typically more susceptible to chemicals.
0
0
文章
Dummer. ゛☀
2017年09月16日
Caterpillars are the larvae of moths and butterflies, and like their winged metamorphoses, they come in all shapes and sizes. While all species share a common appetite for plant foliage, the good news is that the methods for controlling them are basically the same. Before deciding upon a control method, take the time to identify which caterpillars might eventually become the gorgeous butterflies and lovely nocturnal moths we usually welcome to our gardens. These larvae should be protected, and fortunately, most are colorful and harmless.
Caterpillars inflict damage by eating the foliage and stems of just about any plant in your flower or vegetable garden, as well as your fruit and shade trees. Furthermore, they are voracious eaters, and can defoliate a plant in a short period of time. Telltale symptoms of a caterpillar infestation are holes in leaves and chewed leaf edges, as well as leaves that are rolled up or fastened with silk.
If you are able to catch the infestation early on, the best strategy for controlling caterpillars is to handpick them, then crush them or drop them in a pail of soapy water. Make sure you also remove rolled or folded leaves that shelter the caterpillars. (Make sure you wear gloves before handling saddleback caterpillars, as their sting is severe.) To prevent inadvertently killing desirable butterflies- and moths-to-be, use a good field guide such as Peterson First Guide to Caterpillars and pick only those caterpillars which become drab adults.
Cleanup and disposal of garden debris throughout the growing season, followed by a thorough end-of-season cleanup, will help reduce the size of future generations of caterpillars. Furthermore, many insects--such as fireflies, ground beetles, soldier beetles, stink bugs, and tachinid flies-- prey upon or parasitize caterpillars, and will gladly assist you in your quest to keep caterpillar numbers under control.
Specific recommendations for flowers. An effective but less selective control for caterpillars is to dust or spray all parts of the leaves on which they are feeding (especially the undersides) with BT (Bacillus thuringiensis). Apply at 3-5 day intervals, reapplying after rain, until caterpillars cease to be a problem. For an infestation that is out of control, spray all sides of the leaves with pyrethrum; usually two applications spaced 3-4 days apart will solve the problem.
Specific recommendations for vegetables. There are some species of caterpillars that are particularly troublesome in the vegetable garden. Cabbage loopers, as their name suggests, are very fond of cabbage (including the Chinese variety), and will also feed on lima and snap beans, broccoli, brussel sprouts, cauliflower, lettuce, parsley, radishes, rutabagas and turnips. They damage crops by chewing small to large ragged holes in the foliage, and by boring into developing heads of cabbage family crops. The best control strategy is to spray plants with BT (Bacillus thuringiensis) every 2 weeks until pests are under control, or until heads begin to form in the case of cabbage family members. Other effective controls are handpicking; spraying plants with liquefied and strained cabbage loopers, or hot pepper spray; and planting trap crops such as celery or amaranth. For serious infestations, spray leaves with pyrethrum.
Another caterpillar that shares the cabbage looper's taste in plants is the imported cabbage worm. Symptoms of infestation include ragged holes in the leaves and bits of green excrement; you will also notice white butterflies skipping about from plant to plant. Like cabbage loopers, imported cabbage worms eventually bore into the developing heads of cabbage family plants, turning them into mush in the process. The most effective strategy for controlling this pest is to use an agricultural fleece or net barrier and a preventive BT (Bacillus thuringiensis) spray early in the season, then to use more BT for later infestations. A thorough fall cleanup is essential to prevent recurring infestations, since these pests overwinter in the soil or on garden litter. After harvesting crops, promptly remove all old plants and overgrown weeds, leaving the soil completely bare, then cultivate soil to a depth of 6-8 inches. Make sure old plants are actively composted or destroyed.
European corn borers are most notorious for boring holes into the stalks and ears of the corn plant, but also damage chard, peppers, potatoes and tomatoes. Squash vine borers affect crops such as cucumbers, muskmelons, pumpkins, squash (summer and winter), and watermelons by burrowing into their vines and causing them to wilt. For more information on these pests, see Caterpillars - Borers and Miners: Specific recommendations for vegetables.
Parsleyworms are 2 inches long, and are a brightly colored green with yellow-dotted black bands across each body segment. They give off an odor and project orange horns when they are upset. They will someday become lovely, black swallowtail butterflies, so carefully weigh their aesthetic value against the damage inflicted on your carrots, celery, dill, fennel, parsley and parsnip plants before deciding to destroy them. If you decide the parsleyworms are eating excessively into your harvest, reduce their numbers by handpicking them, or try attracting birds such as northern orioles, barn swallows, bluebirds, chickadees, flycatchers and kinglets into your garden.
The tomato hornworm is a large (3 to 5 inches long), green caterpillar with a horn projecting from its rear; it will eventually become a moth whose diurnal feeding habits and ability to hover have earned it the name of "hummingbird moth." The hornworm chews holes in the leaves of dill, eggplant, pepper, potato and tomato plants, and will sometimes also damage the fruits of the latter three. Check damaged plants for dark colored droppings, and spray them with water; this should cause the hornworms to thrash about and enable you to handpick them more easily. If you notice papery cocoons on their backs, remove but don't destroy the caterpillars: they are already doomed by natural parasites, which should be allowed to reproduce. You can also control hornworms with a Bacillus thuringiensis (BT) spray, or a pyrethrum spray if the infestation gets out of hand.
Specific recommendations for trees. This section will address three pests that primarily affect trees: codling moths, gypsy moths, and tent caterpillars. The larvae of codling moths primarily damage apple, apricot and pear crops, both when they are immature and again when they have ripened. Symptoms of infestation include holes in the fruit skin, tunnels through the fruit, and fecal waste in the core; check also for mounds of excrement around the tunnel entrances and for cocoons in the bark crevices. To control this pest, use a preventive spray of Bacillus thuringiensis (BT) early in the season and light horticultural oil later in the season to get the newly hatched larvae before they bore into the fruit. In addition, set out sticky traps to snare the moths during their emergence times (check with orchard growers in your area).
Gypsy moths are imported pests that primarily affect the eastern United States, and their populations fluctuate between sheer nuisance to plague proportions. Their larvae damage host trees by devouring their leaves, often leaving them (and sometimes entire forests) completely defoliated. When the larvae are young, they chew only around leaf edges; by the time they are an inch long, large holes begin to appear in leaves. In July, the mature caterpillars encase themselves in brown shells to pupate. To control this voracious pest, particularly when its population is waxing, spray trees with Bacillus thuringiensis (BT) every 10 to 14 days from late April to mid-June. In June, wrap trunks of vulnerable trees with a piece of burlap a foot wide, hung about chest high; tie it at the center with heavy twine, letting the top fold over to form a skirt. When caterpillars descend from the tree each morning, they will hide under the fold. In the late afternoon, put on garden gloves and sweep the caterpillars off into a container of detergent and water. To prevent future gypsy moth problems, check for egg clusters on lawn furniture before putting it away in the fall, and stone walls, woodpiles, fences, garages and outbuildings throughout the winter. Destroy egg masses by scraping them into a can of kerosene, gasoline or water, or by burning them. Reduce debris on the ground that can serve as protection for egg masses, larvae and pupae.
Tent caterpillars form large, tent-like, silken nests in the forks of tree branches, and can defoliate their woody hosts if given the chance. Remove the nests and destroy the caterpillars by hand. Spray the tree with Bacillus thuringiensis (BT) as soon as you see the nests begin to reappear, and repeat every 5 to 7 days until the pest is gone.
Caterpillars inflict damage by eating the foliage and stems of just about any plant in your flower or vegetable garden, as well as your fruit and shade trees. Furthermore, they are voracious eaters, and can defoliate a plant in a short period of time. Telltale symptoms of a caterpillar infestation are holes in leaves and chewed leaf edges, as well as leaves that are rolled up or fastened with silk.
If you are able to catch the infestation early on, the best strategy for controlling caterpillars is to handpick them, then crush them or drop them in a pail of soapy water. Make sure you also remove rolled or folded leaves that shelter the caterpillars. (Make sure you wear gloves before handling saddleback caterpillars, as their sting is severe.) To prevent inadvertently killing desirable butterflies- and moths-to-be, use a good field guide such as Peterson First Guide to Caterpillars and pick only those caterpillars which become drab adults.
Cleanup and disposal of garden debris throughout the growing season, followed by a thorough end-of-season cleanup, will help reduce the size of future generations of caterpillars. Furthermore, many insects--such as fireflies, ground beetles, soldier beetles, stink bugs, and tachinid flies-- prey upon or parasitize caterpillars, and will gladly assist you in your quest to keep caterpillar numbers under control.
Specific recommendations for flowers. An effective but less selective control for caterpillars is to dust or spray all parts of the leaves on which they are feeding (especially the undersides) with BT (Bacillus thuringiensis). Apply at 3-5 day intervals, reapplying after rain, until caterpillars cease to be a problem. For an infestation that is out of control, spray all sides of the leaves with pyrethrum; usually two applications spaced 3-4 days apart will solve the problem.
Specific recommendations for vegetables. There are some species of caterpillars that are particularly troublesome in the vegetable garden. Cabbage loopers, as their name suggests, are very fond of cabbage (including the Chinese variety), and will also feed on lima and snap beans, broccoli, brussel sprouts, cauliflower, lettuce, parsley, radishes, rutabagas and turnips. They damage crops by chewing small to large ragged holes in the foliage, and by boring into developing heads of cabbage family crops. The best control strategy is to spray plants with BT (Bacillus thuringiensis) every 2 weeks until pests are under control, or until heads begin to form in the case of cabbage family members. Other effective controls are handpicking; spraying plants with liquefied and strained cabbage loopers, or hot pepper spray; and planting trap crops such as celery or amaranth. For serious infestations, spray leaves with pyrethrum.
Another caterpillar that shares the cabbage looper's taste in plants is the imported cabbage worm. Symptoms of infestation include ragged holes in the leaves and bits of green excrement; you will also notice white butterflies skipping about from plant to plant. Like cabbage loopers, imported cabbage worms eventually bore into the developing heads of cabbage family plants, turning them into mush in the process. The most effective strategy for controlling this pest is to use an agricultural fleece or net barrier and a preventive BT (Bacillus thuringiensis) spray early in the season, then to use more BT for later infestations. A thorough fall cleanup is essential to prevent recurring infestations, since these pests overwinter in the soil or on garden litter. After harvesting crops, promptly remove all old plants and overgrown weeds, leaving the soil completely bare, then cultivate soil to a depth of 6-8 inches. Make sure old plants are actively composted or destroyed.
European corn borers are most notorious for boring holes into the stalks and ears of the corn plant, but also damage chard, peppers, potatoes and tomatoes. Squash vine borers affect crops such as cucumbers, muskmelons, pumpkins, squash (summer and winter), and watermelons by burrowing into their vines and causing them to wilt. For more information on these pests, see Caterpillars - Borers and Miners: Specific recommendations for vegetables.
Parsleyworms are 2 inches long, and are a brightly colored green with yellow-dotted black bands across each body segment. They give off an odor and project orange horns when they are upset. They will someday become lovely, black swallowtail butterflies, so carefully weigh their aesthetic value against the damage inflicted on your carrots, celery, dill, fennel, parsley and parsnip plants before deciding to destroy them. If you decide the parsleyworms are eating excessively into your harvest, reduce their numbers by handpicking them, or try attracting birds such as northern orioles, barn swallows, bluebirds, chickadees, flycatchers and kinglets into your garden.
The tomato hornworm is a large (3 to 5 inches long), green caterpillar with a horn projecting from its rear; it will eventually become a moth whose diurnal feeding habits and ability to hover have earned it the name of "hummingbird moth." The hornworm chews holes in the leaves of dill, eggplant, pepper, potato and tomato plants, and will sometimes also damage the fruits of the latter three. Check damaged plants for dark colored droppings, and spray them with water; this should cause the hornworms to thrash about and enable you to handpick them more easily. If you notice papery cocoons on their backs, remove but don't destroy the caterpillars: they are already doomed by natural parasites, which should be allowed to reproduce. You can also control hornworms with a Bacillus thuringiensis (BT) spray, or a pyrethrum spray if the infestation gets out of hand.
Specific recommendations for trees. This section will address three pests that primarily affect trees: codling moths, gypsy moths, and tent caterpillars. The larvae of codling moths primarily damage apple, apricot and pear crops, both when they are immature and again when they have ripened. Symptoms of infestation include holes in the fruit skin, tunnels through the fruit, and fecal waste in the core; check also for mounds of excrement around the tunnel entrances and for cocoons in the bark crevices. To control this pest, use a preventive spray of Bacillus thuringiensis (BT) early in the season and light horticultural oil later in the season to get the newly hatched larvae before they bore into the fruit. In addition, set out sticky traps to snare the moths during their emergence times (check with orchard growers in your area).
Gypsy moths are imported pests that primarily affect the eastern United States, and their populations fluctuate between sheer nuisance to plague proportions. Their larvae damage host trees by devouring their leaves, often leaving them (and sometimes entire forests) completely defoliated. When the larvae are young, they chew only around leaf edges; by the time they are an inch long, large holes begin to appear in leaves. In July, the mature caterpillars encase themselves in brown shells to pupate. To control this voracious pest, particularly when its population is waxing, spray trees with Bacillus thuringiensis (BT) every 10 to 14 days from late April to mid-June. In June, wrap trunks of vulnerable trees with a piece of burlap a foot wide, hung about chest high; tie it at the center with heavy twine, letting the top fold over to form a skirt. When caterpillars descend from the tree each morning, they will hide under the fold. In the late afternoon, put on garden gloves and sweep the caterpillars off into a container of detergent and water. To prevent future gypsy moth problems, check for egg clusters on lawn furniture before putting it away in the fall, and stone walls, woodpiles, fences, garages and outbuildings throughout the winter. Destroy egg masses by scraping them into a can of kerosene, gasoline or water, or by burning them. Reduce debris on the ground that can serve as protection for egg masses, larvae and pupae.
Tent caterpillars form large, tent-like, silken nests in the forks of tree branches, and can defoliate their woody hosts if given the chance. Remove the nests and destroy the caterpillars by hand. Spray the tree with Bacillus thuringiensis (BT) as soon as you see the nests begin to reappear, and repeat every 5 to 7 days until the pest is gone.
0
0
文章
Dummer. ゛☀
2017年09月16日
Aphids are a very large and diverse group of insects that plague the garden especially during the beginning and end of the growing season. At least 4,000 aphid species have been identified; variations in color, size, and appearance make it impossible to generalize.
Symptoms and Diagnosis
Aphid damage may appear as pale yellow spots on leaves, leaves that are curled, puckered, or stunted, and/or distorted blossoms. Look for aphids at the beginning of the growing season. They should be especially abundant on stems and buds where nitrogen concentrations are higher. Aphids multiply more rapidly with high nitrogen levels. Another sign to look for is a sooty black layer on the leaves. Because aphids suck more plant sap than they can use, they exude honeydew onto leaf surfaces. Envied by honeybees and ants, this honeydew substance is very sweet and molds quickly.
Life Cycle
Females lay eggs toward the end of the growing season in the bark or bud scales of their favorite plant. When the eggs hatch the following spring, the nymphs are all female and are called "stem mothers". These females will give live birth to daughters without mating. Toward the end of the growing season, males are produced, mating occurs, and the eggs will again overwinter in the plant material.
Integrated Pest Management Strategies
1. Through good horticultural practices, aphids can be minimized. One step is to control the amount of nitrogen added to the garden. By using slowrelease fertilizers such as ammonium or urea-based fertilizers, compost, decomposed manure, fish emulsion, or liquid seaweed, you slow the rate at which the aphids can reproduce. Another step is to prune moderately in winter and early spring, saving the heavy pruning for midgrowing season. This prevents the aphids from destroying fresh growth in early spring. The last step is to encourage a continuum of flowers that will attract the aphids’ natural predators— ladybugs and praying mantis.
2. Try spraying the aphids off the plants with plain water, or remove them by hand with a cloth.
3. Insecticidal soap can be used, but in moderation, as it will kill beneficial insects as well as the aphids.
4. Insecticidal baits that contain boric acid can be used to control the ants, which have a symbiotic relationship with the aphids. The ants protect the aphids and get the honeydew that they ooze in return. Use caution; boric acid is toxic to people and animals. Ant barriers placed at the base of infested plants is another way to discourage ants and allow predators to attack the aphid population.
5. Silica Aerogel/Pyrethrin is a product that will dissolve the cuticle layer on the insect causing it to dehydrate and die.
6. Use chemical insecticides. Pesticides registered for use include carbaryl (Sevin), disulfoton (Disyston), malathion, bifenthrin, imidacloprid, permethrin, petroleum oil, and pyrethrins.
Symptoms and Diagnosis
Aphid damage may appear as pale yellow spots on leaves, leaves that are curled, puckered, or stunted, and/or distorted blossoms. Look for aphids at the beginning of the growing season. They should be especially abundant on stems and buds where nitrogen concentrations are higher. Aphids multiply more rapidly with high nitrogen levels. Another sign to look for is a sooty black layer on the leaves. Because aphids suck more plant sap than they can use, they exude honeydew onto leaf surfaces. Envied by honeybees and ants, this honeydew substance is very sweet and molds quickly.
Life Cycle
Females lay eggs toward the end of the growing season in the bark or bud scales of their favorite plant. When the eggs hatch the following spring, the nymphs are all female and are called "stem mothers". These females will give live birth to daughters without mating. Toward the end of the growing season, males are produced, mating occurs, and the eggs will again overwinter in the plant material.
Integrated Pest Management Strategies
1. Through good horticultural practices, aphids can be minimized. One step is to control the amount of nitrogen added to the garden. By using slowrelease fertilizers such as ammonium or urea-based fertilizers, compost, decomposed manure, fish emulsion, or liquid seaweed, you slow the rate at which the aphids can reproduce. Another step is to prune moderately in winter and early spring, saving the heavy pruning for midgrowing season. This prevents the aphids from destroying fresh growth in early spring. The last step is to encourage a continuum of flowers that will attract the aphids’ natural predators— ladybugs and praying mantis.
2. Try spraying the aphids off the plants with plain water, or remove them by hand with a cloth.
3. Insecticidal soap can be used, but in moderation, as it will kill beneficial insects as well as the aphids.
4. Insecticidal baits that contain boric acid can be used to control the ants, which have a symbiotic relationship with the aphids. The ants protect the aphids and get the honeydew that they ooze in return. Use caution; boric acid is toxic to people and animals. Ant barriers placed at the base of infested plants is another way to discourage ants and allow predators to attack the aphid population.
5. Silica Aerogel/Pyrethrin is a product that will dissolve the cuticle layer on the insect causing it to dehydrate and die.
6. Use chemical insecticides. Pesticides registered for use include carbaryl (Sevin), disulfoton (Disyston), malathion, bifenthrin, imidacloprid, permethrin, petroleum oil, and pyrethrins.
0
0
文章
Dummer. ゛☀
2017年09月16日
Leaf scorch may occur on any species of tree or shrub as well as herbaceous plants. It is a widespread noninfectious disease or disorder. Scorch most often occurs following prolonged periods of dry, windy weather or bright sunshine when the roots are unable to supply water to the foliage as rapidly as it is lost by transpiration from the leaves. Unfavorable locations, such as sandy or gravelly soil, near obstructions or pavement that restrict root growth, or exposed windy slopes usually promote scorch. Anything that affects the plant’s ability to take up water, including insect and disease problems, can result in leaf scorch. Herbicides and pesticides may also contribute to scorch. Do not spray on windy days to eliminate drift problems and do not allow mist to settle onto trees.
In mild cases of leaf scorch, the leaves remain attached, and little damage results. In more severe cases, plants may drop many of their leaves prematurely, although such plants do not die. Where leaf scorch occurs each year, such annual stress will gradually weaken the plant, making it more susceptible to insects and diseases.
Symptoms and Diagnosis
Browning of leaf margins and/or yellowing or darkening of the areas between the main leaf veins are symptoms of leaf scorch. Due to environmental causes, leaves may dry, turn brown, and become brittle. Look for damage to trees and shrubs on the upper portion on the sunny, southern side and on the windy side. Premature dropping of leaves and twig dieback may occur during the late summer. Symptoms usually appear after drying winds in conjunction with periods of hot, dry weather.
Leaf scorch on narrow leaf evergreens appears as brown or purple brown discoloration of the needle tips. If unfavorable conditions become more severe, browning of needles increases. This should not be confused with the browning and shedding of older interior needles. Scorch may result from hot, dry weather in summer or from strong, dry winter winds when the ground is frozen. Symptoms may not become apparent for a month or more after the initial injury.
Winter leaf scorch in evergreen plants usually appears as two long, brown areas paralleling the main leaf vein.
Life Cycle
Although plants can experience scorch with no insects or disease pathogens involved, insect and disease damage can also affect the plant’s uptake of water. In some cases, insect damage such as leafhopper (hopper burn) or specific scorch diseases caused by fungi or bacteria can produce similar symptoms. Scorch can also reduce the health of a plant making it more susceptible to attack by insects and diseases.
Integrated Pest Management Strategies
1.Water when needed and maintain plant vigor. Plant in a fertile, well-drained soil at the same depth the plants grew in at the nursery and with an adequate supply of organic matter. Soil should be moist to a depth of 10 to 12 inches after a thorough watering. This should be done about once weekly. It is very important for the trees, especially broadleaf and needled evergreens, to be well watered going into the winter period. Water during this period if seasonal rains are not adequate or during the winter when the soil is not frozen. Annuals and perennials require more frequent watering than most trees and shrubs.
2. Fertilize. Fertilize plants in early spring based on a soil test and the directions printed on the fertilizer container. Nitrogen should be applied annually based on the area to be fertilized, the type of plant, and the diameter of the trunk. Do not fertilize with nitrogen in the late fall as it may cause new soft growth easily damaged by cold weather.
3. Mulch. Organic mulches (pine needles, wood chips, composted leaves, pine bark, cypress mulch) can help retain moisture during the summer and fall droughts. In the winter this mulch prevents the alternate freezing and thawing of the soil. Mulch will also cool the soil in summer.
4. Screens. Screens may be used to protect trees and plants in areas exposed to wind and sun, but it is best not to plant tender plants in these exposures.
5. Exposure. Other factors which can result in scorch are excessive fertilizer, deicing salt, herbicide, dog urine, trash fires, leaking sewer or gas mains, girdling roots or strangling wires, vehicle exhaust, and heat reflected from buildings. Elimination of the exposure to these elements is the only correction.
6. Physical hazards. Avoid root injury when digging near trees and shrubs. Care should be taken to not injure the bark and roots when using lawnmowers, weed whips, and edging tools.
In mild cases of leaf scorch, the leaves remain attached, and little damage results. In more severe cases, plants may drop many of their leaves prematurely, although such plants do not die. Where leaf scorch occurs each year, such annual stress will gradually weaken the plant, making it more susceptible to insects and diseases.
Symptoms and Diagnosis
Browning of leaf margins and/or yellowing or darkening of the areas between the main leaf veins are symptoms of leaf scorch. Due to environmental causes, leaves may dry, turn brown, and become brittle. Look for damage to trees and shrubs on the upper portion on the sunny, southern side and on the windy side. Premature dropping of leaves and twig dieback may occur during the late summer. Symptoms usually appear after drying winds in conjunction with periods of hot, dry weather.
Leaf scorch on narrow leaf evergreens appears as brown or purple brown discoloration of the needle tips. If unfavorable conditions become more severe, browning of needles increases. This should not be confused with the browning and shedding of older interior needles. Scorch may result from hot, dry weather in summer or from strong, dry winter winds when the ground is frozen. Symptoms may not become apparent for a month or more after the initial injury.
Winter leaf scorch in evergreen plants usually appears as two long, brown areas paralleling the main leaf vein.
Life Cycle
Although plants can experience scorch with no insects or disease pathogens involved, insect and disease damage can also affect the plant’s uptake of water. In some cases, insect damage such as leafhopper (hopper burn) or specific scorch diseases caused by fungi or bacteria can produce similar symptoms. Scorch can also reduce the health of a plant making it more susceptible to attack by insects and diseases.
Integrated Pest Management Strategies
1.Water when needed and maintain plant vigor. Plant in a fertile, well-drained soil at the same depth the plants grew in at the nursery and with an adequate supply of organic matter. Soil should be moist to a depth of 10 to 12 inches after a thorough watering. This should be done about once weekly. It is very important for the trees, especially broadleaf and needled evergreens, to be well watered going into the winter period. Water during this period if seasonal rains are not adequate or during the winter when the soil is not frozen. Annuals and perennials require more frequent watering than most trees and shrubs.
2. Fertilize. Fertilize plants in early spring based on a soil test and the directions printed on the fertilizer container. Nitrogen should be applied annually based on the area to be fertilized, the type of plant, and the diameter of the trunk. Do not fertilize with nitrogen in the late fall as it may cause new soft growth easily damaged by cold weather.
3. Mulch. Organic mulches (pine needles, wood chips, composted leaves, pine bark, cypress mulch) can help retain moisture during the summer and fall droughts. In the winter this mulch prevents the alternate freezing and thawing of the soil. Mulch will also cool the soil in summer.
4. Screens. Screens may be used to protect trees and plants in areas exposed to wind and sun, but it is best not to plant tender plants in these exposures.
5. Exposure. Other factors which can result in scorch are excessive fertilizer, deicing salt, herbicide, dog urine, trash fires, leaking sewer or gas mains, girdling roots or strangling wires, vehicle exhaust, and heat reflected from buildings. Elimination of the exposure to these elements is the only correction.
6. Physical hazards. Avoid root injury when digging near trees and shrubs. Care should be taken to not injure the bark and roots when using lawnmowers, weed whips, and edging tools.
0
0
文章
Dummer. ゛☀
2017年09月16日
The water needs of different plants vary greatly. Some factors to consider include the species and age of the plant, the type of soil in which it is planted, and its exposure. The symptoms of drought stress may be similar to the symptoms of over watering or even to some pest and disease problems. It is important to identify the causes of the problem in order to take corrective steps.
Symptoms and Diagnosis
With mild water deficiency, plants are usually slow growing and stunted. Some plant leaves turn from shiny to dull at first signs of stress. Grasses, which are the first to show the loss of water in the landscape, will show signs of wilt. Footprints in wilted grass persist instead of disappearing as grass blades spring upright.
Under long term water stress, plants might permanently wilt or stop growing; they may have diminished crops and discolored leaves, flower buds and flowers. Plants may eventually die. Bare spots will appear in ground covers. Water-stressed plantings may show the effects of weeds, insect pests, and diseases.
Drought symptoms can be very confusing, and can vary with different types of plants. Woody plants under drought stress can have many symptoms including yellowing, wilting leaves that develop early fall color and burning or scorching on edges of leaves. Plants may drop some or all of their leaves and appear dead.
Most established woody plants recover when watered. Plants that appear to be dead, having dropped all or most of their leaves, might recover when watered. Scrape the outer layer of a twig or the bark to see if a green layer exists indicating it is still alive. Do not remove this plant the first season. Wait until the following year to see if it recovers.
Integrated Pest Management Strategies
1. Water well. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---drought becomes less of a problem as soils with high humus levels hold more moisture. Take care to keep mulch away from stems.
4. Plant selection. Use appropriate plants, which catalogs and plant tags often marked as drought tolerant or resistant. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary, based on condition of the plant. Most plants will normally wilt in hot sun, and then recover when watered. Also, a dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture.
6. Give priority to watering newly planted trees and shrubs during periods of drought. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Inspect plants several times a week during drought conditions.
Symptoms and Diagnosis
With mild water deficiency, plants are usually slow growing and stunted. Some plant leaves turn from shiny to dull at first signs of stress. Grasses, which are the first to show the loss of water in the landscape, will show signs of wilt. Footprints in wilted grass persist instead of disappearing as grass blades spring upright.
Under long term water stress, plants might permanently wilt or stop growing; they may have diminished crops and discolored leaves, flower buds and flowers. Plants may eventually die. Bare spots will appear in ground covers. Water-stressed plantings may show the effects of weeds, insect pests, and diseases.
Drought symptoms can be very confusing, and can vary with different types of plants. Woody plants under drought stress can have many symptoms including yellowing, wilting leaves that develop early fall color and burning or scorching on edges of leaves. Plants may drop some or all of their leaves and appear dead.
Most established woody plants recover when watered. Plants that appear to be dead, having dropped all or most of their leaves, might recover when watered. Scrape the outer layer of a twig or the bark to see if a green layer exists indicating it is still alive. Do not remove this plant the first season. Wait until the following year to see if it recovers.
Integrated Pest Management Strategies
1. Water well. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---drought becomes less of a problem as soils with high humus levels hold more moisture. Take care to keep mulch away from stems.
4. Plant selection. Use appropriate plants, which catalogs and plant tags often marked as drought tolerant or resistant. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary, based on condition of the plant. Most plants will normally wilt in hot sun, and then recover when watered. Also, a dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture.
6. Give priority to watering newly planted trees and shrubs during periods of drought. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Inspect plants several times a week during drought conditions.
0
0
文章
Dummer. ゛☀
2017年09月16日
Close-up of spots caused by Botrytis blight on Chinese dogwood (Cornus kousa)
Botrytis blight, also know as gray mold, is a fungal disease caused by several species in the genus Botrytis. It affects the buds, flowers, leaves, and bulbs of many plants including: African violet, begonia, chrysanthemum, cyclamen, dahlia, geranium, lily, peony, rose, and tulip. The extent and severity depends on weather conditions and cultural practices. This disease is the primary cause of decay in cut flowers.
Symptoms and Diagnosis
Botrytis blight causes buds and flowers to develop abnormally and turn brown. Flowers may have irregular flecks and brown spots; older flowers tend to rot quickly. Soft, brown spots appear on leaves, stem, and flowers following a cool damp period. Affected parts may be covered with a gray mold following damp, cool weather.
Life Cycle
Botrytis fungi overwinter as sclerotia on dead plant debris in the garden. In the spring, spores form and spread by wind or splashing water to infect dying, wounded, or extremely soft plant tissues. Fungal mycelial strands (web blight) from previously infected plant parts can grow onto healthy plant parts and infect them. The fungus is capable of invading tissue during all periods of the growing season and multiplies rapidly in declining foliage, hence, the need for good sanitation.
Integrated Pest Management Strategies
1. Practice good sanitation. Remove and destroy all infected plant parts as soon as they are observed.
2. Avoid overcrowding. Give adequate space between plants to allow for good air circulation. The fungus thrives in areas that are cool and moist and where plants are overcrowded.
3. Do not overfeed. Avoid fertilizing with excessive amounts of nitrogen. This can cause tender growth that is very susceptible to the fungus. Get a soil test to guide fertilizer practices.
4. Avoid overhead watering. Water on foliage and flowers from overhead irrigation, especially on cool, cloudy days, promotes the disease. Try to keep buds and flowers dry. Water early in the day so the plants have enough time to dry off completely.
5. Use fungicides. Depending upon the susceptibility of the plant to this disease, spray every 10 days with a fungicide. Pesticides registered for use include copper, captan, chlorothalonil (Daconil), mancozeb, maneb, sulfur, and thiophanate methyl (Cleary 3336). Fungicides must be applied in advance of the disease as a protectant.
Botrytis blight, also know as gray mold, is a fungal disease caused by several species in the genus Botrytis. It affects the buds, flowers, leaves, and bulbs of many plants including: African violet, begonia, chrysanthemum, cyclamen, dahlia, geranium, lily, peony, rose, and tulip. The extent and severity depends on weather conditions and cultural practices. This disease is the primary cause of decay in cut flowers.
Symptoms and Diagnosis
Botrytis blight causes buds and flowers to develop abnormally and turn brown. Flowers may have irregular flecks and brown spots; older flowers tend to rot quickly. Soft, brown spots appear on leaves, stem, and flowers following a cool damp period. Affected parts may be covered with a gray mold following damp, cool weather.
Life Cycle
Botrytis fungi overwinter as sclerotia on dead plant debris in the garden. In the spring, spores form and spread by wind or splashing water to infect dying, wounded, or extremely soft plant tissues. Fungal mycelial strands (web blight) from previously infected plant parts can grow onto healthy plant parts and infect them. The fungus is capable of invading tissue during all periods of the growing season and multiplies rapidly in declining foliage, hence, the need for good sanitation.
Integrated Pest Management Strategies
1. Practice good sanitation. Remove and destroy all infected plant parts as soon as they are observed.
2. Avoid overcrowding. Give adequate space between plants to allow for good air circulation. The fungus thrives in areas that are cool and moist and where plants are overcrowded.
3. Do not overfeed. Avoid fertilizing with excessive amounts of nitrogen. This can cause tender growth that is very susceptible to the fungus. Get a soil test to guide fertilizer practices.
4. Avoid overhead watering. Water on foliage and flowers from overhead irrigation, especially on cool, cloudy days, promotes the disease. Try to keep buds and flowers dry. Water early in the day so the plants have enough time to dry off completely.
5. Use fungicides. Depending upon the susceptibility of the plant to this disease, spray every 10 days with a fungicide. Pesticides registered for use include copper, captan, chlorothalonil (Daconil), mancozeb, maneb, sulfur, and thiophanate methyl (Cleary 3336). Fungicides must be applied in advance of the disease as a protectant.
0
0
文章
Dummer. ゛☀
2017年09月15日
Small silver patches and black dots on the leaves. Feeding thrips can also turn petals on flowers brown. New growth can be distorted, browning and curled.
Plants affected
Virtually all garden plants can be affected, from ornamental species, to fruit, vegetable, and cereal crops. Flowers and leaves of plants are most affected.
About Thrips
Thrips are sometimes known as thunderflies or thunderbugs.
There are over 3000 recorded species worldwide, with over 150 in the UK.
They are typically small, slender, dark-coloured insects about 2mm long or less and usually have two pairs of feather-like wings.
Thrips rasp through upper leaf cells to feed on plant sap, causing a silvering appearance.
Thrip droppings are minute black specks on the leaves.
Thrips have six lifecycle stages including egg, larvae, pupa and adult.
Larvae and pupae can be a lighter colour than adults.
Females have a serrated tube for laying eggs into plant tissue.
They are predominantly a summer pest, favouring warm temperatures and dry conditions.
Thundery conditions trigger swarming.
Some species can transmit viruses such as tomato spotted wilt virus.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Thrips
Pyrethrins
Methiocarb
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Release the predatory mite Amblyseius cucumeris, and predatory bug Orius laevigatus.
Spray organic plant oils approved for use on plants.
Remove and destroy infested leaves, particularly silvery areas where eggs are present.
Prevention
Thoroughly clean greenhouses at the end of the season to remove any over-wintering thrips.
Use sticky traps to monitor the first appearance of thrips. Blue coloured traps are thought to be more effective than other colours.
Netting and fleeces can be used as a barrier between plants.
Plants affected
Virtually all garden plants can be affected, from ornamental species, to fruit, vegetable, and cereal crops. Flowers and leaves of plants are most affected.
About Thrips
Thrips are sometimes known as thunderflies or thunderbugs.
There are over 3000 recorded species worldwide, with over 150 in the UK.
They are typically small, slender, dark-coloured insects about 2mm long or less and usually have two pairs of feather-like wings.
Thrips rasp through upper leaf cells to feed on plant sap, causing a silvering appearance.
Thrip droppings are minute black specks on the leaves.
Thrips have six lifecycle stages including egg, larvae, pupa and adult.
Larvae and pupae can be a lighter colour than adults.
Females have a serrated tube for laying eggs into plant tissue.
They are predominantly a summer pest, favouring warm temperatures and dry conditions.
Thundery conditions trigger swarming.
Some species can transmit viruses such as tomato spotted wilt virus.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Thrips
Pyrethrins
Methiocarb
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Release the predatory mite Amblyseius cucumeris, and predatory bug Orius laevigatus.
Spray organic plant oils approved for use on plants.
Remove and destroy infested leaves, particularly silvery areas where eggs are present.
Prevention
Thoroughly clean greenhouses at the end of the season to remove any over-wintering thrips.
Use sticky traps to monitor the first appearance of thrips. Blue coloured traps are thought to be more effective than other colours.
Netting and fleeces can be used as a barrier between plants.
0
0
文章
Dummer. ゛☀
2017年09月15日
Botrytis infects plant material above ground which is usually dead or dying. Depending on the species of the plant and the fungus there may be different symptoms at different times of year. A common sign of botrytis is a grey mould on leaves, stems, fruits, flowers and buds. Before the mould appears symptoms include dead brown patches on leaves, stems and buds, white or pale brown spots on petals and fruit, and rotting on unplanted bulbs.
Plants affected
Most fruit and vegetables, some houseplants, ornamentals, shrubs and trees.
About Grey mould
There are many species of botrytis with different infection methods. They cause a range of symptoms before the fuzzy grey mould appears including dead brown patches on leaves, stems and buds, white or pale brown spots on petals and fruit, and rotting on unplanted bulbs.
The spores will attack weak or dying plants in preference to healthy ones.
Conditions must be cool and humid for plants to be infected.
The fungal phase can only survive a narrow range of temperatures.
Botrytis overwinters as small, dark, hard structures, called sclerotia, on plant debris and other surfaces.
When spring weather conditions are favourable they produce spores. These are dispersed by wind, air movement, water splash and pesticide sprays.
Once a plant is infected, botrytis may spread to all parts depending on its species and variety.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Grey mould
Myclobutanil
Penconazole
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regular observation is essential to prevent infections establishing.
Remove all dead and injured plant material before it can become infected.
Remove infected leaves, fruits and buds by cutting right back into healthy growth. Bin or burn the infected material to help reduce the spread of infection.
Isolate infected plants to reduce infection spread.
Place fleece between plants to reduce the movement of spores.
Prevention
Regularly check plants for signs of infection and deal with them as soon as they appear.
Ensure greenhouses are always well ventilated.
Space plants out to reduce the humidity around them and prevent infections establishing.
Reduce the humidity in greenhouses and around houseplants to prevent infections establishing.
Plants affected
Most fruit and vegetables, some houseplants, ornamentals, shrubs and trees.
About Grey mould
There are many species of botrytis with different infection methods. They cause a range of symptoms before the fuzzy grey mould appears including dead brown patches on leaves, stems and buds, white or pale brown spots on petals and fruit, and rotting on unplanted bulbs.
The spores will attack weak or dying plants in preference to healthy ones.
Conditions must be cool and humid for plants to be infected.
The fungal phase can only survive a narrow range of temperatures.
Botrytis overwinters as small, dark, hard structures, called sclerotia, on plant debris and other surfaces.
When spring weather conditions are favourable they produce spores. These are dispersed by wind, air movement, water splash and pesticide sprays.
Once a plant is infected, botrytis may spread to all parts depending on its species and variety.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Grey mould
Myclobutanil
Penconazole
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regular observation is essential to prevent infections establishing.
Remove all dead and injured plant material before it can become infected.
Remove infected leaves, fruits and buds by cutting right back into healthy growth. Bin or burn the infected material to help reduce the spread of infection.
Isolate infected plants to reduce infection spread.
Place fleece between plants to reduce the movement of spores.
Prevention
Regularly check plants for signs of infection and deal with them as soon as they appear.
Ensure greenhouses are always well ventilated.
Space plants out to reduce the humidity around them and prevent infections establishing.
Reduce the humidity in greenhouses and around houseplants to prevent infections establishing.
0
0
文章
Dummer. ゛☀
2017年09月15日
The larvae of several moth and butterfly species (listed below) are collectively referred to as tent caterpillars. Distributed throughout much of the United States and Canada, these caterpillars multiply rapidly and can defoliate a large number of deciduous trees and shrubs in a short time. They are often seen on roadside trees and in neglected orchards. Besides defoliation the larvae produce large unsightly webs, or tents, in the crotches of tree branches. These webs are used to protect the caterpillars from predators and the elements. Although tent caterpillar damage is unsightly, infestations rarely threaten the lives of trees.
Four species are commonly discussed:
Eastern Tent Caterpillar (Malacosoma americanum) – Found east of the Rockies and north into southern Canada. Full grown caterpillars (2 inches long) are sparsely hairy and black in color with a row of pale blue spots on each side. They have a white stripe down the center of their backs that makes them easy to identify. Adults (1-1/2 inches long) are reddish brown moths with two white bands running diagonally across each forewing. Host plants include cherry, apple and crabapple, but may be found on a variety of shade trees as well.
Western Tent Caterpillar (Malacosoma californicum) – Troublesome in the northern and western portions of the United States and adjoining Canada. These hairy caterpillars (2 inches long) are yellowish-brown in color and have a row of blue spots on their backs, with orange spots interspersed in between. Adult moths (1-1/2 inches long) are orange-brown in color with two narrow yellow lines on the wings. Willow, poplar, cottonwood, birch, apple, plum, cherry, roses and oak are favorite host plants of this pest.
Forest Tent Caterpillar (Malacosoma disstria) – Found throughout the United States and Canada wherever hardwoods are found. Despite its name, this pest does not spin a true tent; instead, it forms a silken mat on the surface of branches where they congregate. Larvae are similar in appearance to M. americanum but have a series of keyhole-shaped white spots running down their back instead of a solid line. Adults are light yellow to tan colored moths (1-1/2 inch long) with two dark bands on their forewings. Host plants include wild cherry, aspen, maple, oak and hawthorn.
Fall Webworm (Hyphantria cunea) – Common across North America and Mexico, webworms are known to feed on over 85 species of trees. Unlike tent caterpillars that build a nest in the crotch of trees, webworm tents are located at the outer ends of branches and often include leaves. Caterpillars (1 inch in length) are covered with long hairs and vary in color from yellow to green, with a black stripe on the back and a yellow stripe on each side. Their heads are either red or black. Adult moths (1 inch long) are pure white in color and usually have dark spots on the wings.
Life Cycle
Most species of tent caterpillars overwinter in the egg stage. Dark brown to gray egg masses containing 150 to 400 eggs are attached around the small twigs of trees and shrubs. Hatching takes place about the time that leaf buds begin to unfold, usually in early spring. Caterpillars are gregarious and soon construct silken tents which they uses as a refuge during the early morning and evening hours and during rainy spells. They leave their protective tent and feed only during the day, laying down a silk trail as they crawl to help them find their way back to the shelter. Approximately six weeks after hatching, and five instars later, the larva become fully grown (up to 2 inches long, sparsely hairy). Pupation occurs in silken cocoons which are found on tree trunks, fences, or leaf litter. About two weeks later adult moths emerge and soon deposit the overwintering eggs. There is one generation a year.
Note: Larvae can be a nuisance when they begin to migrate to protected areas to pupate. They are often found by the thousands traveling over roads, streets, driveways, walkways, fences and buildings.
Tent Caterpillar Control
Scrape off and discard overwintering egg masses and tear the protective tents out by hand before the larvae start to feed.
Restrict caterpillar movement and cut off access to feeding areas with Sticky Tree Bands or Tree Tanglefoot Pest Barrier.
The natural, soil dwelling bacterium Bacillus thuringiensis or Bt-kurstaki is particularly effective on inch worms of all types. Use easily applied spray to hit worms and protect the leaves at the first signs of damage. BTK sprays do not harm honey bees or birds and are safe for use around pets and children.
Spinosad, another biological agent derived from fermentation, is also very effective. It’s the active ingredient in Monterey Garden Insect Spray, a product classified as organic by the U.S.D.A. National Organic Program and listed for organic use by the Organic Materials Review Institute.
Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This effective spray disrupts growth and development of pest insects and has repellent and anti-feedant properties. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Four species are commonly discussed:
Eastern Tent Caterpillar (Malacosoma americanum) – Found east of the Rockies and north into southern Canada. Full grown caterpillars (2 inches long) are sparsely hairy and black in color with a row of pale blue spots on each side. They have a white stripe down the center of their backs that makes them easy to identify. Adults (1-1/2 inches long) are reddish brown moths with two white bands running diagonally across each forewing. Host plants include cherry, apple and crabapple, but may be found on a variety of shade trees as well.
Western Tent Caterpillar (Malacosoma californicum) – Troublesome in the northern and western portions of the United States and adjoining Canada. These hairy caterpillars (2 inches long) are yellowish-brown in color and have a row of blue spots on their backs, with orange spots interspersed in between. Adult moths (1-1/2 inches long) are orange-brown in color with two narrow yellow lines on the wings. Willow, poplar, cottonwood, birch, apple, plum, cherry, roses and oak are favorite host plants of this pest.
Forest Tent Caterpillar (Malacosoma disstria) – Found throughout the United States and Canada wherever hardwoods are found. Despite its name, this pest does not spin a true tent; instead, it forms a silken mat on the surface of branches where they congregate. Larvae are similar in appearance to M. americanum but have a series of keyhole-shaped white spots running down their back instead of a solid line. Adults are light yellow to tan colored moths (1-1/2 inch long) with two dark bands on their forewings. Host plants include wild cherry, aspen, maple, oak and hawthorn.
Fall Webworm (Hyphantria cunea) – Common across North America and Mexico, webworms are known to feed on over 85 species of trees. Unlike tent caterpillars that build a nest in the crotch of trees, webworm tents are located at the outer ends of branches and often include leaves. Caterpillars (1 inch in length) are covered with long hairs and vary in color from yellow to green, with a black stripe on the back and a yellow stripe on each side. Their heads are either red or black. Adult moths (1 inch long) are pure white in color and usually have dark spots on the wings.
Life Cycle
Most species of tent caterpillars overwinter in the egg stage. Dark brown to gray egg masses containing 150 to 400 eggs are attached around the small twigs of trees and shrubs. Hatching takes place about the time that leaf buds begin to unfold, usually in early spring. Caterpillars are gregarious and soon construct silken tents which they uses as a refuge during the early morning and evening hours and during rainy spells. They leave their protective tent and feed only during the day, laying down a silk trail as they crawl to help them find their way back to the shelter. Approximately six weeks after hatching, and five instars later, the larva become fully grown (up to 2 inches long, sparsely hairy). Pupation occurs in silken cocoons which are found on tree trunks, fences, or leaf litter. About two weeks later adult moths emerge and soon deposit the overwintering eggs. There is one generation a year.
Note: Larvae can be a nuisance when they begin to migrate to protected areas to pupate. They are often found by the thousands traveling over roads, streets, driveways, walkways, fences and buildings.
Tent Caterpillar Control
Scrape off and discard overwintering egg masses and tear the protective tents out by hand before the larvae start to feed.
Restrict caterpillar movement and cut off access to feeding areas with Sticky Tree Bands or Tree Tanglefoot Pest Barrier.
The natural, soil dwelling bacterium Bacillus thuringiensis or Bt-kurstaki is particularly effective on inch worms of all types. Use easily applied spray to hit worms and protect the leaves at the first signs of damage. BTK sprays do not harm honey bees or birds and are safe for use around pets and children.
Spinosad, another biological agent derived from fermentation, is also very effective. It’s the active ingredient in Monterey Garden Insect Spray, a product classified as organic by the U.S.D.A. National Organic Program and listed for organic use by the Organic Materials Review Institute.
Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This effective spray disrupts growth and development of pest insects and has repellent and anti-feedant properties. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
0
0
文章
Dummer. ゛☀
2017年09月15日
Common on backyard trees, ornamental shrubs, greenhouse plants and houseplants, over 1,000 species of scale insects exist in North America. They are such oddly shaped and immobile pests that they often resemble shell-like bumps rather than insects. In many cases, heavy infestations build up unnoticed before plants begin to show damage. Large populations may result in poor growth, reduced vigor and chlorotic (yellowed) leaves. If left unchecked, an infested host may become so weak that it dies.
Scale insects can be divided into two groups:
Armored (Hard) – Secrete a hard protective covering (1/8 inch long) over themselves, which is not attached to the body. The hard scale lives and feeds under this spherical armor and does not move about the plant. They do not secrete honeydew.
Soft – Secrete a waxy film (up to 1/2 inch long) that is part of the body. In most cases, they are able to move short distances (but rarely do) and produce copious amounts of honeydew. Soft scale vary in shape from flat to almost spherical.
Life Cycle
Adult females lay eggs underneath their protective covering which hatch over a period of one to three weeks. The newly hatched nymphs (called crawlers) migrate out from this covering and move about the plant until a suitable feeding site is found. Young nymphs insert their piercing mouthparts into the plant and begin to feed, gradually developing their own armor as they transform into immobile adults. They do not pupate and may have several overlapping generations per year, especially in greenhouses.
Note: Males of many species develop wings as adults and appear as tiny gnat-like insects. They are rarely seen and do not feed on plants. Females often reproduce without mating.
Control
To get rid of scale insects prune and dispose of infested branches, twigs and leaves.
When scale numbers are low they may be rubbed or picked off of plants by hand.
Dabbing individual pests with an alcohol-soaked cotton swab or neem-based leaf shine will also work when infestations are light.
Commercially available beneficial insects, such as ladybugs and lacewing, are natural predators of the young larval or “crawler” stage.
Organic pesticides, like insecticidal soap and d-Limonene can also be used to kill the larvae. However, these products have very little persistence in the environment, so several applications during egg-hatching will be required for effective control.
Azamax contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated spray is approved for organic use and offers multiple modes of action, making it virtually impossible for pest resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Horticultural oils and other safe, oil-based insecticides work by smothering insects and will control all pest stages, including adults which are protected from most other insecticides by their armor coverings.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Scale insects can be divided into two groups:
Armored (Hard) – Secrete a hard protective covering (1/8 inch long) over themselves, which is not attached to the body. The hard scale lives and feeds under this spherical armor and does not move about the plant. They do not secrete honeydew.
Soft – Secrete a waxy film (up to 1/2 inch long) that is part of the body. In most cases, they are able to move short distances (but rarely do) and produce copious amounts of honeydew. Soft scale vary in shape from flat to almost spherical.
Life Cycle
Adult females lay eggs underneath their protective covering which hatch over a period of one to three weeks. The newly hatched nymphs (called crawlers) migrate out from this covering and move about the plant until a suitable feeding site is found. Young nymphs insert their piercing mouthparts into the plant and begin to feed, gradually developing their own armor as they transform into immobile adults. They do not pupate and may have several overlapping generations per year, especially in greenhouses.
Note: Males of many species develop wings as adults and appear as tiny gnat-like insects. They are rarely seen and do not feed on plants. Females often reproduce without mating.
Control
To get rid of scale insects prune and dispose of infested branches, twigs and leaves.
When scale numbers are low they may be rubbed or picked off of plants by hand.
Dabbing individual pests with an alcohol-soaked cotton swab or neem-based leaf shine will also work when infestations are light.
Commercially available beneficial insects, such as ladybugs and lacewing, are natural predators of the young larval or “crawler” stage.
Organic pesticides, like insecticidal soap and d-Limonene can also be used to kill the larvae. However, these products have very little persistence in the environment, so several applications during egg-hatching will be required for effective control.
Azamax contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated spray is approved for organic use and offers multiple modes of action, making it virtually impossible for pest resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Horticultural oils and other safe, oil-based insecticides work by smothering insects and will control all pest stages, including adults which are protected from most other insecticides by their armor coverings.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
0
0
