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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Hail can severely damage all plants. The severity of the damage depends on the size of the hailstones and the time of the year that the hailstorm occurs. The later in the growing season that hail damage occurs the less time plants have to recover and store energy for the winter.
Symptoms and Diagnosis On annuals and perennials leaves, stems and flowers may be shredded, torn and knocked off. On trees and shrubs leaves, twigs and branches may be tattered, split and broken. Fruit may be pitted and knocked to the ground. The scars from hail damage to trees occur on the upper side of branches and on the side of the trunk facing the storm. The tree may take a very long time to recover. The damage increases the vulnerability of the tree to decay causing fungi and insect activity.
Integrated Pest Management Strategies 1. Evaluate damage. Assess the damage to the plants and estimate how long they have left to recover from the damage before the onset of winter. 2. Cleanup. Severely damaged trees and shrubs with broken branches should have them removed promptly. Less severe wounds may slowly heal naturally over a period of time. Damaged fruit should be removed. Do not fertilize hail damaged trees. 3. Fertilize. If the damage is early in the growing season, annuals and perennials may benefit from a light application of fertilizer. Immediately remove any damaged leaves from these plants.
4. Replace. Annuals and perennials that do not show signs of recovery within a week should be replaced with new plants. 5. Give good after care. Water the damaged plants during the growing season giving them at least one inch of water each week. 6. Mulch. Applying two to three inches of mulch around the base of damaged plants may help them survive during the winter.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Foliar nematodes, Aphelenchoides spp., are considered disease-causing organisms that attack plant parts above the ground in over 200 host plants. They are an emerging problem for gardeners because of this broad host range, ability to spread quickly and lack of symptom recognition. Additionally, there are few products registered for use in the home landscape that can limit their infection and spread. Some of the most common hosts include anemone, strawberry, hosta, phlox, verbena, zinnia, carnation, impatiens, begonia, fern and African violet.
Symptoms and Diagnosis The two most prominent foliar nematodes are A. ritzemabosi called the chrysanthemum foliar nematode and A. fragariae called the strawberry crimp or fern nematode. Both are serious pathogens of ornamental plants both in the greenhouse and outside in the garden. However, their host ranges rarely overlap except on African violet, begonia, gloxinia, Siberian bugloss, violet and verbena. The most prominent symptoms occur in the leaves of infected plants. Two interveinal symptom types are commonly found. The first is a development of linear lesions between the leaf veins causing the leaf to become striped in appearance. Plants that have parallel venation like hosta are likely to display this leaf pattern. The second leaf symptom which is more common is the development of angular, water-soaked lesions occurring between the veins of netted-veined plants. These lesions will become brown and eventually turn black and perhaps drop out of the leaf leaving a ragged, wind-tattered appearance. Other symptoms may appear as stunting, leaf proliferation or bunching of leaves around the crown, multicolored leaves, lack of flowering and plant death. It is not uncommon to find new leaves emerging without symptoms while older leaves turn brown and collapse or fall. This occurs because the spread of nematodes requires free moisture. Lack of water on the leaves causes them to become localized so that they cannot move to new plant parts. Thus, under dry conditions, new leaves may appear unaffected.
Life Cycle Unique to this group of pathogens, foliar nematodes live in and feed upon the aerial portion of the plant, mostly leaves, and are rarely associated with the soil unless it is within infested plant debris. A common over wintering site is within the crown of the plant where new leaves will emerge in spring. They commonly spread from plant to plant by splashing water and leaf contact. Nematodes can swim in a thin film of water to move upward towards leaves where they enter stomata. Another way they spread is by vegetative cuttings of leaves, stems and crowns. Gardeners who are active in propagation are likely to move the pathogen with every division. Nematodes remain active, feeding on leaf tissue and repeating their life cycle multiple times in the growing season. Once it becomes cooler, they will migrate towards the plant crown, live in dormant buds or leaf debris.
Integrated Pest Management Strategies 1. Sanitation: remove all infested debris from the plant and ground. This should be buried or burned. Floors and benches of propagation areas should be thoroughly cleaned of debris. Tools and containers should be heat treated in an oven or steamed for 30 minutes at 180 F. 2. Destroy infested plants: it is almost impossible to rid the plant of foliar nematodes. Therefore, it is best to destroy infested plants. Plants that are suspected of being infected should be isolated from healthy plants. 3. Select disease-free plants: Only healthy, nematode-free plants should be purchased and used for propagation stock. Contact between plants and extended periods of free moisture from overhead irrigation should be avoided. Dormant plant material can be treated with warm water (120 F) for 15 minutes to eliminate the nematode infestation on valuable planting stock.
4. Resistance: Some resistant cultivars of chrysanthemum are available. At this time, no resistant varieties are known for other garden plants. 5. Pesticides: Commercial growers who are certified for using nematicides can control foliar nematodes on greenhouse and nursery crops. There are no nematicides labeled for residential users.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
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.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Sclerotia of southern blight (resembling mustard seeds) at the crown of Japanese anemone (Anemone) Crown rot, sometimes called southern blight or southern stem rot, is caused by several soil-borne fungi. It affects herbaceous plants and some woody plants but is most commonly found on ajuga, anemone, campanula, chrysanthemum, delphinium, hosta, hydrangea, iris, narcissus, phlox, rudbeckia, scabiosa, sedum, and tulip. The problem generally requires removal of the diseased plant.
Symptoms and Diagnosis Crown rot causes deterioration and rotting of the tissues at the crown of the plant causing the leaves to turn yellow, collapse, and die. When the temperature exceeds 70 degrees F, infected plants develop discolored, water-soaked stem lesions near the soil line. During periods of high humidity, coarse cottony webbing (mycelium) develops and fans out over the stem base and surrounding soil. Sclerotia, which resemble mustard seeds and vary from white to reddish tan to light brown in color, develop at the base of the plant. Enough sclerotia may form to create a crust on the soil.
Life Cycle The fungi which cause crown rot (Pellicularia rolfsii, Sclerotium delphinii, and Sclerotium rolfsii) survive in the soil and are spread by flowing water, transported or contaminated soil, transplants, and tools. Conditions of 86–95 degrees F for several days with intermittent rains are conducive for fungal development.
Integrated Pest Management Strategies 1. Remove diseased plants as soon as they are noticed. Plants can be buried, but do NOT place them in your compost pile. 2. Excavate surrounding soil. Dig out and replace the soil to a depth of 8 inches and 6 inches beyond the diseased area. 3. Solarize the soil. If you do not remove the soil and the area receives at least two to three hours of direct sun, solarize it. Cover the area with clear plastic and leave it for two to three months in the heat of the summer.
4. Provide better drainage. Increasing the organic content of the soil and improving drainage will make the environment less desirable to the fungus. 5. Sterilize all tools. Clean all tools used in digging with a solution of 1–part bleach to 9–parts water to disinfect the tools and reduce spreading the disease to other locations in your garden. 6. Try fungicides. Pesticides registered for control of crown rot include mancozeb and thiophanate methyl (Cleary 3336).
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Pea-sized brown flower buds characteristic of bud-blast on peony (Paeonia) A frequent problem on peonies is failure of flower buds to open in spring. Typically, the flower buds develop to about the size of a pea and then fail to develop further. There are several possible causes. In a narrower interpretation bud-blast only includes environmental and cultural problems. In a broad interpretation bud-blast includes fungal diseases that affect flower buds. Following are the most common reasons why peony buds may fail to open.
Botrytis blight Botrytis blight, also called gray mold, is a common fungal disease of many plants including peonies. It commonly affects the new shoots and foliage of peonies (see Botrytis Blight of Peony herein) but can also affect young flower buds. The young buds turn brown and fail to open. Once affected, a flower bud cannot be saved. To address the disease in subsequent years follow the practices outlined in "Botrytis Blight of Peony."
Cold temperatures in early spring When the young peony flower buds are subjected to cold temperatures in early spring as they begin to develop growth may stop when they are about the size of a pea. They may take on a reddish appearance but do not become brown and papery as in botrytis blight. Nor do they develop the gray mold characteristic of botrytis blight. Later in the season, however, the buds will brown and fall off. If possible, relocate peonies to a location where they are less subject to late spring freezes or protect plants when freezing temperatures are forecast.
Too much shade, lack of proper fertilization, or drought Anything that stresses the plant could result in bud-blast. This can include too much shade – peonies prefer full sun, lack of adequate fertilization in poor soil, or a period of drought when the plants are making active growth and buds are developing in spring. Provide the plants with adequate sun, fertilizer and moisture, especially in early spring when they are making active growth.
Plants are too young or have been recently divided Newly planted or divided and transplanted peonies may take a year or two to become established before they flower normally. Be patient and give the plants good care.
Organic Strategies Since bud-blast of peony is most often caused by environmental stresses, correcting the source of stress is the best way to prevent it. Proper site selection, as well as good division, planting and watering techniques are all organic approaches to preventing this condition. Proper fertilization is also recommended, and the use of organic fertilizers would be a viable organic approach as well.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Botrytis blight on peony foliage (Paeonia) Gray mold or botrytis blight is caused by the fungus, Botrytis paeoniae. It is the most common disease of garden peonies. This destructive disease is very prevalent during damp, rainy seasons.
Symptoms and Diagnosis On peonies afflicted with botrytis, the young shoots rot off at ground level when they are 5 to 8 inches tall. The stems often have a water-soaked, cankerous appearance. The leafy shoots wilt suddenly and fall over. The rotted portion of the plant will become covered with a soft brown or blackish mass of spores. Just above the ground level, the stalk will be covered with a gray mold which sheds large numbers of spores. The spores are carried by wind and insects to young leaves and flower buds and cause a leaf blight and bud rot. Small buds that are affected turn black and wither. Larger buds turn brown and fail to open. During a severe outbreak of the disease, 90% of the buds fail to develop. Open flowers are affected occasionally, and they also turn brown and later develop a covering of gray mold.
Life Cycle Botrytis fungi are both saprophytic and parasitic. The spore-producing structures of the fungus develop along the base of the rotting stalks and survive in debris left in the garden over the winter. In the spring, spores form and spread to dying, wounded, or extremely soft plant tissues. As the disease progresses, a gray mold develops. The gray mold is made up of spores that are either wind-blown or splashed onto new tissues and infect.
Integrated Pest Management Strategies 1. Prevent infection. In early fall, cut down all old leaves and stalks to ground level. This debris should be destroyed and not composted. Apply 1 to 2 inches of mulch to bury debris. 2. Improve soil drainage. Plant peonies in welldrained soil; heavy clay soils should be lightened with organic material such as compost or peat moss. They should not be planted so that water is apt to cover their bases, nor should soil be heaped about the leaf bases.
3. Move plants to a better location. Good air circulation can reduce disease problems. Plant in full sun or at least in part sun. Space plants widely, at least 3 feet apart. Remove aging leaves from plants. 4.Use disease-free roots. When planting new plants, buy only from reputable dealers, or take divisions only from healthy, disease-free plants. 5. Use a fungicide. Spray the plants with a fungicide when young tips break through the ground. Follow 2 weeks later with another application and every 14 days thereafter until mid-June. 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. 6. Look for varieties that show some resistance to the disease.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
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.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Distorted flowers on purple coneflower (Echinacea purpurea) caused by aster yellows Aster yellows is a viral-like disease caused by a phytoplasma (formerly called a mycoplasma-like organism). Insects that suck the sap of plants, especially the aster leafhopper, vector the disease. Aster leafhoppers are insects that annually migrate northward from their winter home in areas along the Gulf of Mexico. Aster yellows is a disease that affects over 300 species of plants, including ornamentals such as aster, coneflower, zinnia, marigold, chrysanthemum, petunia, and snapdragon. Edibles affected include lettuce, carrot, tomato, and celery. Grasses and grains also are hosts. Weeds that may harbor the disease include plantain, dandelion, and other broad-leafed weeds.
Aster yellows is primarily transmitted by leafhoppers. When a leafhopper feeds on a plant infected with aster yellows it becomes "infected" with the phytoplasma and remains infected throughout its life. The phytoplasma cells multiply and cause infection of the insect’s salivary glands within one to three weeks. When the infected insects feed on healthy plants, they inject the phytoplasma cells into the plant phloem. Susceptible plants will be symptomatic in 10 to 40 days. The spread of aster yellows is worse in cool, wet summers. Hot dry weather is not favorable for either the phytoplasma or the leafhopper. As with many disease and pest problems, diagnosis is perhaps the most important factor in controlling aster yellows.
A somewhat similar appearing problem on coneflowers is caused by an eriophyid mite. Experts are still sorting this problem out but the lower pictures on this page may be caused by this yet unnamed eriophyid mite. At present the common name used for this disorder is coneflower rosette mite. It may be a controllable problem through sanitation practices (disposal of all affected flowers as they appear and all foliage in the fall) unlike aster yellows for which there is no cure other than to destroy infected plants.
Symptoms and Diagnosis Chlorosis, yellowing of the leaves while the veins remain green, is a major symptom of aster yellows. Growth slows down and leaves may be smaller and more narrow than usual. Foliage is sometimes curled. Flowers may be deformed and exhibit bizarre tufts of deformed leaves inside the flower or in place of the flower. Flowers may not produce seeds. The symptoms of the disease will often differ depending upon what species is infected. For instance, carrot roots may be bitter and hairy while lettuce may show pink or tan spots and have twisted inner leaves.
Integrated Pest Management Strategies 1. Remove diseased plants. Once a plant is infected with aster yellows, it is a lost cause since the disease is incurable. Early diagnosis and prompt removal of infected plants may help reduce the spread of the disease. Although the disease itself is not fatal to the plant, its presence makes it impossible for a plant to fulfill its intended role in the garden. 2. Plant less susceptible plant species. Controlling aster yellows is difficult. As long as infected leafhoppers are around, they can infect plants. A practical way to avoid having problems with this disease is to grow plants that are not as susceptible to aster yellows. Verbena, salvia, nicotiana, geranium, cockscomb, and impatiens are among the least susceptible plants.
3. Control insects. Vegetable growers may protect susceptible crops by using the mesh fabrics that keep leafhoppers and other insects away from the plants. Some growers put strips of aluminum foil between rows because bright reflections of sunlight confuse the leafhoppers. 4. Control weeds. Remove weeds in your lawn, garden, and surrounding areas, including plantain and dandelion that may harbor the disease.
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Dummer. ゛☀
2017年09月16日
Dummer. ゛☀
Alternaria blight on zinnia (Zinnia) - left leaf; bacterial leaf spot on zinnia - right leaf Only two diseases are commonly troublesome on zinnias (Zinnia elegans), powdery mildew and Alternaria blight. Alternaria blight is the most common and conspicuous.
Symptoms and Diagnosis Spotting of the foliage caused by the fungus, Alternaria zinniae, is the most conspicuous symptom of zinnia blight. Individual spots are at first circular in outline but rapidly become irregular. The spots may vary from 2 to 10 millimeters or more in diameter, are reddish brown, and have grayish-white centers on the upper leaf surface. Differentiation of margin and center is lacking on the lower surface. As the spots increase in size and number, they coalesce and the affected leaves become brown and dry.
Blossoms may be severely affected. Brown spots, 1 or 2 millimeters in diameter, with grayish-white centers sometimes appear on the petal tissues of the ray flowers. Affected plants soon darken and wither, causing blossoms to become unsightly. Numerous, small, reddish spots, sometimes with grayish-white centers, may be seen on stem internodes. Such spots usually are superficial. Spots that develop at nodes, however, usually do not remain superficial. Instead, they grow or coalesce into larger lesions that frequently girdle the stem causing the upper portions of the affected stem to die back to the node. Dark brown to black cankers with sunken centers are also common at the base of the stem of diseased plants. Affected plants often wilt completely, even when the basal cankers do not encircle the stem.
The outer tissues of affected roots may become dark gray, rot completely, and slough off, resulting in wilting and death of the plant. Damping-off of seedlings also may occur. Life Cycle The fungus survives on seeds and in the soil associated with host debris. Midsummer and early fall are normal times of outbreak. Integrated Pest Management Strategies 1. Sanitation. Clean up debris; bury or burn if possible. Fungus may remain associated with plant material for 2 years. 2. Rotation. Use a long crop rotation of three years if growing commercially. A two-year rotation schedule is satisfactory for home garden and small isolated areas where disease spread can be limited.
3. Resistant varieties. Use resistant varieties of Zinnia elegans when possible. But be warned, no cultivars to date have been found to be totally resistant to Alternaria blight. 4. Propagation. Seeds may be infected with the fungus. Before planting, treat the seeds by placing them in hot water at 125 degrees F for 30 minutes. Then cool and dry. Older seeds can be injured by this treatment.
5. Watering. Do not use overhead irrigation. Water at the base of plants. 6. Fungicides. Use protectant fungicides. Spray seedlings and young plants with azoxystrobin (Heritage), chlorothalonil (Daconil), copper, ferbam, mancozeb, or maneb.
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Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
The pine tree lappet moth (Dendrolimus pini) is a native of continental Europe, Russia and Asia, where it causes periodic, large-scale damage to pine plantations. This damage sometimes covers thousands of hectares, with outbreaks lasting up to eight years in some parts of its range. Outbreaks and resultant defoliation by pine tree lappet moth caterpillars can impair tree growth and tree health, making trees more susceptible to other organisms such as bark beetles and wood-boring insects, the effects of which could ultimately lead to tree deaths. This could lead to significant ecological, economic and, ultimately, social impacts.
Distribution In Scotland, adult male moths were first caught in 2004 in a pine plantation to the west of Inverness, and then in the river Beauly catchment, but the presence of this moth was not reported to the Forestry Commission until 2008. There have been occasional sightings of single specimens on the south coast of England and in the Channel Islands. These were probably ‘migrant’ males blown across the English Channel. There is a report that a caterpillar found in Essex in 1999 on a pine tree imported from Italy was bred out to produce a female moth. It was first recorded in Scotland in 2004.
Its natural range is the Scots pine forests of continental Europe, where it is widespread, occurring in every European country as well as Russia and parts of Asia. It has also been reported in North Africa. Spread The moths move mainly by flying, although the female moths are very heavy (with eggs) and therefore do not usually fly further than a few hundred metres. Older caterpillars are able to crawl from tree to tree – but can also crawl as much as several hundred metres to reach new stands of trees. Eggs, larvae and pupae could also be spread on harvested logs being transported on lorries, or on plants or foliage. We do not yet know how the moth got here. It could have been brought in on imported pine trees, on forestry machinery from abroad, or with wood products or wood packaging - but it is also possible that it might have been accidentally or deliberately released. We have no information that would confirm which of these possible routes could have led to the current finds, and it remains most unlikely that we will be able to trace-back unless further DNA testing finds a very close match to an overseas source population.
Lifecycle Adult moths emerge from pupae in midsummer and live for 9-10 days, during which time they mate. The females each deposit up to 250 eggs on twigs, needles and the bark of host trees. These hatch within 16-25 days, and the caterpillars feed on pine needles in the tree canopy until winter frosts begin, when they then move down the trees to over-winter between the litter and soil close to the base of trees. Pine-tree lappet moth caterpillar eating Scots pine needle. Location: Northern Research Station, Roslin, Midlothian, Scotland.In spring the caterpillars return to the tree crowns and continue feeding until they are large enough to pupate.
The caterpillars moult through several, progressively larger stages, growing to as much as 8.0 cm long. Pupation begins in May and June and lasts for 4-5 weeks. Pupae are formed inside loose, partially transparent cocoons, which can be found in tree crowns, bark crevices and under-storey vegetation. In laboratory conditions it is possible for development from egg to adult to take place in only 6-7 months. In field conditions under our current climate a two-year cycle is believed to be the norm, but a one-year life-cycle under favourable conditions, and a three-year lif-ecycle under less favourable conditions, cannot be discounted.
In Europe natural enemies include several bacteria and fungi (particularly on the over-wintering caterpillars), parasitoids (e.g. parasitic wasps and flies) and predators such as ants and birds, which will feed on or attack the larvae. Bats will catch the adults. A number of species of insects have been reported to prey on the moth.
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