动态第770页 - 绿手指 - 养花技巧、花生病了怎么办、花园打理和设计

2017年09月14日

Springtails are tiny, wingless, moisture-loving creatures that seek dampness outdoors and in. They are frequently found clustered together in dense swarms. When disturbed, they spring into the air, as high as several inches, creating easily visible clouds.[图片]Outside, they’re found in wet soil, decaying straw, rotting leaves and other damp organic material. They feed on molds, fungi and algae. As soils dry, the insects search out more moist conditions, a move that often brings them inside homes where they gather in garages, basements and greenhouses as well in damp floorboards, carpets, under kitchen sinks and in the soil of potted houseplants. No longer considered true insects because of their internal chewing mechanism — insects have external chewing parts — springtails make up the order Collembola. They can be as much as 1/16 inch long but before reaching maturity are just a fraction this size. They come in all shades of brown and gray as well as black and white.[图片]Springtails become conspicuous as they gather in large clusters that resemble balls or swatches of fabric. Springing into the air, seemingly all at once, when exposed or disturbed, makes them even more conspicuous. This leaping is done by means of an external body part known as a furcula which is folded under its abdomen. When released, the furcula pops the tiny bug a few inches into the air. Life Cycle Springtails reproduce quickly, going from egg to adult stage in as little as four to six weeks. Mature males leave packets of sperm cells in the soil where they live. These are picked up by females as they lay their eggs, either in packets or singly. Depending on temperature conditions, the eggs hatch within five to ten days.[图片]Nymphs resemble the adults. During the five or six weeks they spend as nymphs, they go through several stages before becoming adults, molting and becoming larger in each. Outdoors, springtails can survive through an entire season, reproducing a number of times. Indoors, they can live as long as a year. Damage Springtails are mostly a nuisance pest, doing little damage to plants. They will chew roots in the soil where they’re located, and can inhibit plant hardiness. But they seldom do major damage.[图片]These nearly invisible bugs do not bite or sting and are generally harmless to humans. But they are an unpleasant house guest and finding a swarm of them under a carpet or around a basement drain requires cleanup to prevent ongoing populations or masses of dead insects that are less than sanitary. The presence of springtails in your bathroom or carpets is an indication of dampness that provides clues to possible larger problems such as leaky pipes or roofs, poorly sealed tubs and sinks and porous basement walls. Treating pest infestations often requires house repairs and other fixes. Springtails will cluster inside the walls of newly built homes that were exposed to rain or high humidity during framing and not allowed to completely dry. The pests presence inside walls can be an indication that mold and fungus might be present. Springtails can be a major nuisance around outdoor swimming pools where they will often cover the water’s surface as they die off. Though they hold no danger to humans, this bug scum makes for a poor pool experiences. The creature’s tiny size and great numbers can make them difficult to skim.[图片]Hydroponics and Indoor Garden Control Because of their moisture levels, indoor growing spaces are particularly susceptible to springtail infestations. In hydroponic growing systems, the pests will cluster at the edge of grow-tank and in exposed root crowns of plants. Careful periodic inspections and removal can help keep populations down. While it’s often claimed that springtails do little noticeable damage, they will feed on roots and moist plant matter, causing “leaf stipling” (yellowing) and cause other harm to growth and vigor. Still, many growers choose to tolerate them rather than treat them. If you choose to co-exist with them, make sure you’ve positively identified them and aren’t mistaking them for some pest like spider mites that can cause extensive damage. Wipe up pest colonies around the rims of trays, near drains and other damp places in your grow space. Large colonies on floors or on stands can be vacuumed with a shop-vac. If springtails have become such a nuisance they must be sprayed, use an OMRI listed for organic production compound such as azadirachtin, an anti-feedant and insect growth regulator (IGR) that controls pests through starvation and growth disruption.[图片]Potted Plants Springtails enter homes through window screens, open doors and windows, vent pipes or in potted plants. They are attracted to indoor moisture, especially as the outdoors dries. They may be attracted to light, entering through windows, under doors or through cracks in the foundation. Keep springtails away from your home by keeping leaves, grass and other organic matter away from the foundation. Fill every crack the foundation may have, even beneath the soil line as possible. Make sure seals around windows and doors are tight. Use crawling insect killers with diatomaceous earth to repel the pests around places where they might enter. Springtails frequently occur in the soil of potted plants. Inspect the potting mixture of every plant you intend to bring home by testing it with your thumbs and watching for springing. Lichen or other soil covers that are organic food sources for the pests should be examined carefully. Be especially cautious if plants show signs of excess moisture. If you suspect insect activity, quarantine house plants, preferably outside, to allow the soil to completely dry before bringing them in.[图片]Letting soil dry completely as possible is the best way to deal with infested pots already in the home. Sprinkle Safer Brand diatomaceous earth on potted soils to help them dry and to repel springtails. If infestations in potted plants persist, use a non-toxic, biodegradable soil drench to kill and repel the bugs. (More than one application may be required.) After a hot day, they may congregate on the side of a building in tremendous numbers, increasing the chance of indoor infestation. If you spot an infestation inside or out, use a wet -dry shop-vac with a small amount of soapy water in its collection tank to vacuum them up. Use fans to thoroughly dry any area of the house, including inside walls (as possible) where springtails have been found. Repair roof leaks, cracks in siding and any other places where moisture might enter the house. Keep areas around sink faucets and drains clear and clean of molds and other growth that might used as a food source. Remove scum and hair from beneath sink drains. If you suspect springtails in your drain pipes, clean as thoroughly as possible and rinse them with vinegar. (Never pour any type of pesticide down a drain.) House plant soil, especially those with lichen or moss, can be a hotbed of springtail reproduction. Inspect any potted houseplants you buy for signs of infestation before bringing them inside. Once inside the house, don’t over water. Allowing soil to dry completely between watering discourages them from staying around.[图片]Outdoor Control Because they only infrequently damage plants, there’s little reason to control springtails outdoors unless their numbers become a nuisance. The comprehensive Integrated Pest Management website at the University of California says outdoor use of pesticides aren’t effective against this pest and won’t provide long-term control by themselves. To discourage the bugs in gardens and landscapes, remove their favored habitat, namely damp, organic matter. Compacted mulch protects colonies that thrive beneath it. Refrain from adding compost and other organic material to the soil until the pests have disappeared.[图片]Allowing soils to dry completely before watering prevents them from getting established, sending them away in search of wetter territory. Reduce watering in vegetable or ornamental gardens that host springtails and allow soils to dry completely before watering. Don’t expect to eliminate them entirely where moist conditions naturally persist. Frequent turning of straw mulches and compost heaps, disturbs eggs and exposes nymphs to drier surface conditions helping to keep their numbers down. But because of their size, many will escape.

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2017年09月14日

Many species of the spider mite (family: Tetranychidae), so common in North America, attack both indoor and outdoor plants. They can be especially destructive in greenhouses. Spider mites are not true insects, but are classed as a type of arachnid, relatives of spiders, ticks and scorpions. Adults are reddish brown or pale in color, oval-shaped and very small (1/50 inch long) – about the size of the period at the end of this sentence. Immature stages resemble the adults except only smaller.[图片]Mites live in colonies, mostly on the underside of leaves, and feed by piercing leaf tissue and sucking up the plant fluids. Feeding marks show up as light dots on the leaves. As feeding continues, the leaves turn yellow and may dry up and drop off. Spider mites are most common in hot, dry conditions, especially where their natural enemies have been killed off by insecticide use. Some of the many species common in North America are predators of the plant-feeding mites, which make up the vast majority. They are also very prolific, which is why heavy infestations often build up unnoticed before plants begin to show damage. Large populations are often accompanied by fine webbing. Host plants are many and include strawberries, melons, beans, tomatoes, eggplant, ornamental flowers, trees and most houseplants.[图片]Life Cycle Most mite species overwinter as eggs on the leaves and bark of host plants. In early spring, as temperatures warm, tiny six-legged larvae begin hatching and feed for a few days before seeking shelter where they molt into the first nymphal stage. Nymphs have eight-legs and pass through two more molts before becoming mature adults. After mating, females continuously produce as many as 300 eggs over a couple of weeks. Hot, dry weather favors rapid development of these pests. During such conditions the time it takes to pass from egg to adult may occur in as little as 5 days. There are several overlapping generations per year.[图片]Note: Spider mites are wind surfers. They disperse over wide areas riding their webbing on the breezes. Careful containment and disposal of infested plants is crucial. Damage Spider mites, almost too small to be seen, pass into our gardens without notice. No matter how few, each survives by sucking material from plant cells. Large infestations cause visible damage. Leaves first show patterns of tiny spots or stipplings. They may change color, curl and fall off. The mites activity is visible in the tight webs that are formed under leaves and along stems. The University of California Agricultural and Natural Resources division’s Integrated Pest Management website says the following about the damage mites cause: On annual vegetable crops — such as squash, melons and watermelons — loss of leaves can have a significant impact on yield and lead to sunburning. On crops such as sugar peas and beans, where pods are attacked, spider mites can cause direct damage. On ornamentals, mites are primarily an aesthetic concern, but they can kill plants if populations become very high on annual plants. Spider mites are also important pests of field-grown roses.[图片]Control Chemical pesticide use actually encourages the spread of spider mites by killing the beneficial insects that prey on them. Mites are also known to develop quick resistance to various pesticides. For these reasons, it’s important to control mites with effective natural and organic methods. Prune leaves, stems and other infested parts of plants well past any webbing and discard in trash (and not in compost piles). Don’t be hesitant to pull entire plants to prevent the mites spreading to its neighbors. Use the Bug Blaster to wash plants with a strong stream of water and reduce pest numbers. Commercially available beneficial insects, such as ladybugs, lacewing and predatory mites are important natural enemies. For best results, make releases when pest levels are low to medium.[图片]Nuke Em, a relatively new organic insecticide containing food-grade ingredients, works fast and kills most indoor gardening pests at the egg, larvae or adult stage. Best of all, it does this without leaving a residue on the leaves that can impact flavor. If populations are high, use a least-toxic, short-lived pesticide (Take Down Spray, Doktor Doom Foggers) to reduce infestations, then release predatory mites to maintain control.[图片]Insecticidal soap, neem oil or botanical insecticides can be used to spot treat heavily infested areas. On fruit trees, horticultural oil should be applied early in the season or late in the fall to destroy overwintering eggs. Dust on leaves, branches and fruit encourages mites. A mid-season hosing (or two!) to remove dust from trees is a worthwhile preventative. Water stress makes both trees and garden plants more susceptible to mite infestations. Make sure your plants are properly watered.

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2017年09月14日

Often found in home gardens and landscaped areas across the country, sowbugs (Porcellio scaber) and pillbugs (Armadillidium vulgare), also known as rolly pollies, feed primarily on decaying matter and are important in the decomposition process. However, if present in large numbers they have been known to feed on seedlings, new roots, lower leaves and fruits or vegetables laying directly on the soil. These small scavengers scurry when disturbed and are often found outside hiding under leaves, rocks, garden debris, mulch and other dark, damp areas. Occasionally they will enter homes as accidental invaders. Indoors they are simply a nuisance and cannot survive for more than a day or two without water. These insects do not bite or sting and cannot damage household structures.[图片]Similar in appearance, sowbugs and pillbugs (3/4 inch long) are slow-moving oval-shaped crustaceans that more closely resemble crayfish, shrimp and lobster than insects. They vary from gray to brown to almost purple in color and have seven pairs of legs, elbowed antennae, and a segmented hard shell-like covering, similar to that of an armadillos. Sowbugs also have two tail-like structures on the rear end that pillbugs lack. Note: Pillbugs are sometimes called “roly-polies” because they often roll up into a tight ball when disturbed.[图片]Life Cycle Both sowbugs and pillbugs mate throughout the year with most of the activity occurring in March and April. The female incubates her eggs in a fluid-filled pouch (marsupium) located on the underside of her body for 3-7 weeks. After hatching, the young nymphs (similar in appearance to adults, only smaller) remain in the pouch for up to two months until they can care for themselves. Nymphs molt, or shed their exoskeleton, at regular intervals and reach sexual maturity, usually within a year. As adults, they continue to molt about once every month. Females can produce broods of approximately 30-40 young that may live up to 3 years. There are one to two generations per year, depending on weather conditions.[图片]Sowbug/ Pillbug Control To get rid of rolly polly bugs reduce the habitat favored by these pests by eliminating garden debris, leaf piles, fallen fruit and weeds from all growing areas. Use mulches that are coarse enough to let water pass through easily so the surface next to plants will not remain damp for long. Improve air circulation around plants by providing trellises for vines and raising fruits, such as strawberries and melons, up off the ground. Diatomaceous earth, made from the finely ground fossils of prehistoric fresh water diatoms (one-celled shells), is abrasive to crawling insects and can be used as a barrier to protect plants.[图片]Apply Insect Killer Granules around foundations, lawns and landscaped areas to eliminate or repel all kinds of troublesome pests. Scatter Monterey Ant Control, a safe and organic bait containing iron phosphate and spinosad, evenly over the soil around or near problem areas. Apply fast-acting botanical insecticides as a soil drench if pest levels become intolerable.

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2017年09月14日

Sod webworms live in the thatch, just above the soil, where they spin a light webbing and feed on the undersides of leaves. Damage first appears as small, ragged brown spots in the turf. As feeding continues these areas become larger and may join other large dead patches of grass. Damage occurs on most turfgrasses including bluegrass, bentgrass, tall and fine-leafed fescues and buffalo grass and is most prevalent in areas that receive plenty of direct sunlight or south-facing slopes. Heavily shaded areas are seldom attacked.[图片]The sod webworm (1 inch long) is the larval or caterpillar stage of a small white-brown moth (1/2 to 3/4 inches long) with pale yellow or brown markings on their wings. The adult moths have a habit of folding their wings up closely to their bodies when at rest, earning the group the name “close-winged moths.” If disturbed, the moths fly in a zig zag pattern for short distances before settling again. Adults do not feed on lawns. Life Cycle Sod webworms overwinter as young larvae in silk-lined tunnels near the soil surface or in the thatch. They resume feeding as temperatures warm in April or early May and pass through several instars until their development is complete. In early June, webworms pupate in loosely woven cocoons made of silk and bits of dirt. Approximately 10-14 days later adult moths emerge and begin mating. Mated females fly just above the lawn surface and randomly scatter their eggs into the grass. Each female may lay several hundred eggs which hatch into a new generation of larvae within a week. Young larvae spin webs and feed until mid-summer. There are two to three generations per year in most areas.[图片]Sod Webworm Control Water regularly and reduce thatch and other horticultural stresses on lawns. For light to moderate infestations use a soap drench (2 Tbsp. liquid soap per gallon of water) to draw caterpillars up to the lawn surface, then rake and destroy. Beneficial nematodes are a very effective biological control for use against this pest. For best results, water the lawn a day or two prior to applying the nematodes and water the lawn again, immediately after application. The natural, soil dwelling bacterium Bacillus thuringiensis or Bt-kurstaki is particularly effective on webworms. Use the easy-to-apply liquid spray (1 Tbsp/ gallon) to hit pests and protect your turf at the first signs of damage. Repeat at 5-7 day intervals, if needed. BTK sprays do not harm honey bees or birds and are safe for use around pets and children.[图片]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 USDA’s National Organic Program and listed for organic use by OMRI. Mix 2 oz/ gallon (3 gallons of spray treats 1,000 sq ft). Delay watering and mowing after application for 12-24 hours.[图片]Safer® Insecticidal Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed. Least-toxic 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.

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2017年09月14日

Slugs and snails are some of the most troublesome pests found in home gardens, orchards and landscaped areas across North America. They thrive in damp, shady spots and can often be found along foundations, under rocks or in well mulched garden areas.[图片]Most active at night, they feed on a variety of living plants as well as on decaying plant material. Pests chew large holes in foliage and may cause extensive damage to seedlings, tender, low-growing, leafy vegetables and ripening fruit such as strawberries, artichokes and tomatoes. Almost all garden vegetables, ornamental flowers, and some fruit trees, especially citrus are subject to attack. Snails/Slugs are not true insects, but rather members of the mollusk phylum. As a result, they are closely related to snails in structure and biology except the snail has a shell and the slug does not. Both garden pests rely on their muscular foot to move and the secretion of mucous or slime on which they glide. This shiny slime trail often gives them away as it marks their travel.[图片]Life Cycle Several slug species overwinter in the soil as adults or nearly mature young. In spring and early summer large numbers of eggs are deposited (as many as 100 at a time) in soil cracks, underneath mulch or dead leaves and in other cool, moist protected areas. Eggs develop and hatch in 1-3 weeks, but may require as long as 12 weeks if conditions are less than perfect. Once hatched, the young mollusks remain close to the nest for several days until branching out in search of food. Development to maturity may take as little as 3 to 6 months or as long as a year or more depending on species.[图片]Note: Slugs are hermaphrodites, which means that they each possess both male and female sexual organs and have the potential to lay eggs. Snail and Slug Control To get rid of snails and slugs remove garden debris, bricks, lumber piles and weeds from all growing areas and do not apply heavy layers of mulch around plants (1-3 inches is plenty). Handpicking pests can make a sizable dent in the population and is most productive in the evening, two hours after sunset. If handpicking is inconvenient, try trapping. Strips of cardboard, cabbage leaves, rocks or plywood all make excellent traps for daytime collecting. Shallow pans of stale beer sunk into the soil can also be used. The yeast in the beer attracts these pests, which fall in and drown. For best results, replace beer every few days or after a rain.[图片]Copper Tape and diatomaceous earth are popular barriers that prevent pests from reaching the leaves, fruits and flowers on which they feed. Broadcast weather-resistant boric acid granules around flower gardens, ground covers and ornamentals to eliminate slugs and snails. Reapply every four weeks, as needed. Sluggo is an organic bait, containing iron phosphate, that can be scattered on the lawn or on the soil around any vegetables, flowers, fruit trees or bushes to reduce pest numbers.

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2017年09月14日

Many species of the root maggot exist in home gardens throughout North America. Particularly destructive to early season plantings, they feed underground on succulent roots and attack a large variety of vegetable crops including radish, cabbage, carrot, turnip and onions. Heavily infested roots are often riddles with tunnels and rotted. Affected plants lack vigor, may be stunted or yellowed and often wilt during the heat of the day. In some cases, maggots may even chew through taproots, causing plants to die.[图片]Adults (1/5 inch long) are dark gray flies that look like the common housefly, only smaller. They lay their eggs in the soil at the base of host plants and are very good at detecting newly planted seed beds. Maggots (1/3 – 1/4 inch long) are small, yellowish white, legless larvae with tapered or pointed heads and a rear end that is blunt. Note: Tunneling and feeding by this pest creates entry points for rot diseases such as black rot.[图片]Life Cycle Adults emerge in the spring or early summer from overwintering pupal cocoons in the soil. They soon mate and females begin depositing 50-200 small, white eggs in plant stems right at the soil line or in cracks in the soil near plant stems. Eggs hatch in a few days and the larvae burrow down into the soil to feed on small roots, root hairs, and germinating seeds. After feeding for 1-3 weeks, maggots begin to pupate in plant roots or the surrounding soil. There are several generations per year.[图片]Root Maggot Control Female flies are attracted for egg laying by the moisture emitted from newly planted seed rows. Cover seedbeds with floating row cover immediately after seeds are sown to prevent problems. Be sure the cover extends at least 6 inches on each side of the seed rows. Apply small amounts of Diatomaceous Earth around seedling stems to deter egg laying by adults.[图片]Yellow Sticky Traps placed around vegetable crops will capture many adult flies before they can mate and lay eggs. Heavy paper collars or other sturdy material may be placed around the base of transplants to prevent egg laying around stems. Applying beneficial nematodes in seed furrows or as a top dressing around plants can be effective in getting rid of the larvae. Using a pyrethrin drench is also an effective option, but should only be considered as a last resort. Roto-till under crop debris immediately after harvest to destroy overwintering sites.

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2017年09月14日

Sometimes called jumping plant lice, psyllids feed on a variety of plants including most fruit trees and small fruits as well as tomato and potato. Both adults and nymphs feed by piercing the leaf surface and extracting cell sap. This causes foliage (especially the upper leaves) to turn yellow, curl and eventually die. Honeydew secreted by the psyllids encourages the growth of dark sooty molds. Many species transmit disease-carrying viruses.[图片]Adults (1/10 inch long) are reddish brown in color with transparent wings and strong jumping legs. They are very active and will hop or fly away when disturbed. Nymphs are flat and elliptical in shape, almost scale-like. They are less active than adults and are most numerous on the undersides of leaves. Newly hatched nymphs are yellowish in color but turn green as they mature.[图片]Note: Psyllids are monophagous which means that they are host specific (each species feeds on only one plant type). Life Cycle Adults overwinter in crevices on tree trunks. In early spring they mate and females begin depositing orange-yellow eggs in the crevices about the buds, and after the foliage is out, on the leaves. Hatching occurs in 4-15 days. Yellow to green nymphs pass through five in instars in 2-3 weeks before reaching the adult stage. There are one to five generations per year depending on species. Psyllid Control To get rid of psyllids spray horticultural oil in early spring to destroy overwintering adults and eggs. Beneficial insects, such as ladybugs and lacewing, are important natural predators of this pest. For best results, make releases when pest levels are low to medium.[图片]If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control. Diatomaceous earth contains no toxic poisons and works quickly on contact. Dust lightly and evenly over vegetable crops wherever adults are found. Safer® Insecticidal Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.[图片]Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from insect pests. 70% Neem Oil is approved for organic use and can be sprayed on vegetables, fruit trees and flowers to kill eggs, larvae and adult insects. Mix 1 oz/ gallon of water and spray all leaf surfaces (including the undersides of leaves) until completely wet. If pest levels become intolerable, spot treat with insecticides approved for organic use every 5-7 days. Thorough coverage of both upper and lower infested leaves is necessary for effective control.

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2017年09月14日

Colorado potato beetles (Leptinotarsa decemlineata) are such a common pest in home gardens that they are often just called “potato bugs.” Both the adult and larval forms chew leaves and can completely defoliate an entire crop if potato beetle control methods are not implemented. Their feeding can greatly reduce yield and in some cases, may even kill plants. Alternate host plants include tomatoes, peppers and eggplant.[图片]Adults (1/3 inch long) are rounded, yellowish-orange beetles with black stripes on their wings and black spots just behind the head. The plump larvae (1/8 to 1/2 inch long) are red with black head and legs, and become yellowish-red or orange with two rows of black spots on each side of the body. Life Cycle Overwintering beetles hibernate in the soil or garden debris, emerging in the spring. At this point, they do not have enough energy to fly and must walk in search of suitable host plants. Females lay orange-yellow eggs in clusters on the undersides of leaves. In 4-15 days (depending on temperature) hatching occurs, and the voracious larvae begin feeding on foliage for up to one month. When mature, they drop from the plant, enter the soil and pupate, emerging as adults 5-10 days later. There are 1 to 3 generations each year.[图片]Potato Beetle Control Plant resistant cultivars when possible. In early morning, shake adults beetles from plants onto ground cloth and dump captured pests into soapy water. To impede the movement of overwintering adults, mulch at least 2-3 inches deep with a layer of clean straw or hay as soon as plants emerge. Protect plants with Harvest-Guard row cover through spring. Beneficial insects, such as ladybugs, spined soldier bugs and lacewing, feed on eggs and the young larval stages. Beneficial nematodes will attack the immature stages developing in the soil.[图片]Diatomaceous earth contains no toxic poisons and works on contact. Dust lightly and evenly over vegetable crops wherever pest insects are found. Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from chewing pests. Monterey Garden Insect Spray (Spinosad) is a highly effective bio-pesticide recommended for use against potato beetles. For best results, apply when young.[图片]Azatrol EC 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 insect resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects. Spot treat with fast-acting organic pesticides if pest levels become intolerable. After harvest pick up garden debris and turn the soil over around plants to disturb overwintering beetles.

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Dummer. ゛☀

2017年09月14日

The Mexican bean beetle (Epilachna varivestis) is one of the most destructive insect pests of beans in the eastern United States and portions of the southwest. Both the adult and the larval stages feed on the undersides of the leaves, and sometimes will attack young pods and stems. As a result of feeding, only the veins are left, giving the leaves a lacy appearance. Damage is most severe in July and August and occurs on all bean varieties, including bush, pole, lima, pinto, navy, kidney, soybeans and cowpeas. Bush varieties seem to be attacked more readily than pole varieties.[图片]Adult beetles (1/4 inch long) are similar in appearance to large ladybugs. They are yellow to coppery-brown in color, oval in shape, and have 16 black spots on their wing covers. Larvae (1/3 inch long) are fat, hump-backed grubs with fuzz or spines, arranged in six longitudinal rows on their backs. They are orange to yellow in color and attach themselves to leaf surfaces.[图片]Life Cycle Adults overwinter in plant debris and other protected areas and emerge when the weather warms up in mid-to-late spring (usually when beans begin sprouting). After feeding for 1 to 2 weeks females begin to deposit yellow eggs in groups of 40 to 60 on the undersides of bean leaves. Larvae hatch in 5 to 14 days and feed for 2 to 5 weeks before pupating on the undersurfaces of leaves. Adults emerge 3 to 10 days later and live from 4 to 6 weeks. The period from egg to adult is about 30-70 days, depending on temperature. There are several generations each growing season. Mexican Bean Beetle Control Since damage is most severe during summer months, consider planting early maturing bean varieties to reduce pest problems. Hand pick the adults and immature stages from plants and drop them in a pail of soapy water. Also, remove the bright yellow eggs laid in clusters on the undersides of leaves.[图片]Harvest-Guard can be used as a physical barrier to keep beetles and grubs from damaging plants. Beneficial insects, such as ladybugs, green lacewing and minute pirate bugs, are all voracious predators of both the egg and young larval stage. Diatomaceous earth contains no toxic poisons and works quickly on contact. Dust lightly and evenly over vegetable crops wherever pest insects are found. Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from chewing pests. Spot treat with Safer Soap or other insecticidal soap and neem combinations. Thorough coverage of both upper and lower leaves is necessary for effectiveness.[图片]Azatrol EC 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 insect resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects. If pest levels become intolerable, spot treat with fast-acting botanical insecticides as a last resort. Treatments should be repeated in 7-10 days if additional beetles are found.

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Dummer. ゛☀

2017年09月14日

Found in greenhouses, home gardens and landscaped areas across the country, leafminers are the larval (maggot) stage of an insect family that feeds between the upper and lower surfaces of leaves. On heavily infested plants it is not uncommon to find 6 or more maggots per leaf. Although damage can restrict plant growth, resulting in reduced yields and loss of vigor, healthy plants can tolerate considerable injury. Host plants include beans, blackberries, cabbage, lettuce, peppers, and a variety of ornamental flowers, trees and shrubs.[图片]Adults (1/10 inch long) are often black to gray flies with yellow stripes and clear wings. They are similar in appearance to small, hunched-back house flies and lay their eggs on the undersides of leaves. Larvae are worm-like maggots (1/3 inch) which are often pale yellow or green in color. They create winding tunnels that are clear, except for the trail of black fecal material (frass) left behind as they feed. Note: In some cases, pathogenic fungi and bacteria may enter old mines left from eradicated insects. This can cause leaves to turn yellow and drop.[图片]Life Cycle Mature larvae overwinter in the soil under host plants. As temperatures warm in the spring larvae pass to the pupal stage and appear as young adults in late April. Mated females use their needle-like ovipositor to lay up to 250 eggs just under the surface of the leaf epidermis. Deposited eggs may appear as small raised spots on the leaf. Within 10 days hatching larvae tunnel through the mid-leaf tissue, feeding as they go and leaving tell-tale wavy lines that are visible on the surface. Larvae mature in 2-3 weeks, and when ready to pupate, leave the leaf and drop to the soil. Once on the ground, they dig 1-2 inches into the soil and pupate. Adults emerge within 15 days as adult flies. There are several generations per year.[图片]Damage Various types of leafminers attack various kinds of plants. They’re found on broadleaf trees, including elm, aspen, hawthorn, and poplar as well as shrubs and bushes, including lilacs. Damage can be limited in initial stages of infestations but increase as leafminer numbers multiply, and even minor infestations, while not killing a plant, will cripple its hardiness. Leafminers are a major cause of poor harvest numbers in home gardens as they weaken individual vegetable plants. They’re especially fond of spinach leaves and their tunneling severely decreases the attractiveness and value of the crop.[图片]Leafminer Control Natural, and organic control methods work best when fighting leafminer problems. That’s because they don’t harm the naturally occurring beneficial insect populations that largely keep the leafminer and other harmful pests under control. While pesticide use can encourage leafminer outbreaks, natural controls and beneficial insects prevent as well as cure these pest problems. Don’t wait until you spot leafminer tunnels in your plants’ leaves, especially if you’ve had problems with them in the past. Be prepared with the products you’ll need to prevent and destroy infestations. Then stay vigilant.[图片]Monitor plant leaves closely. At the first sign of tunneling, squeeze the leaf at the tunnel between two fingers to crush any larvae. Done soon enough, this killing larvae can allow plants to survive minor outbreaks. Pick off and destroy badly infested leaves in small gardens. The more healthy the plant, the less chance that leafminers will hurt it. Maintain plant health with organic fertilizers and proper watering to allow plants to outgrow and tolerate pest damage. Keep your soil alive by using compost and other soil amendments. Use floating row covers (Harvest-Guard) to prevent fly stage from laying eggs on leaves. The parasitic wasp Diglyphus isaea is a commercially available beneficial insect that will kill leafminer larva in the mine. The wasp is especially beneficial to indoor growers of ornamentals and vegetables.[图片]Use yellow or blue sticky traps to catch egg laying adults. Cover soil under infested plants with plastic mulches to prevent larvae from reaching the ground and pupating. Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated 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.

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😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

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