|The magnolia scale belongs to a group of insects described as soft
scales. Scale insects are immobile for most of their life cycle and
thus show little resemblance to the usual form of insects.
Scale insects feed by inserting their syringe-like mouth parts into the plantís vascular system, sucking out sap and other vital plant fluids. Large amounts of these fluids are withdrawn, concentrated in the gut of the scale, and excreted as a clear, sticky liquid ñ honeydew. The honeydew drips onto the leaves and stems making them sticky as well as providing an ideal place for the black sooty mold fungus to develop. The honeydew also attracts ants and wasps which feed on it.
"Bumps on the twigs" is a phrase which can be used to describe these insects. The mature female scales are large, up to 1/2 inch (12.5mm) in diameter, elliptical and convex in shape. Adult scales are permanently affixed to the branches of the host. They range from pink-orange to dark brown in color.
Immature and mature females are often covered with a white waxy bloom. The presence or absence of the wax is the major field character used to distinguish between the magnolia and the tuliptree scale, both of which feed on magnolia.
Immature scales are much more flattened than the adults, but still elliptical in shape. The overwintering nymphs are dark bluish-black, about 1 mm long and clustered on twigs in incredible numbers.
The magnolia scale reaches maturity in August each year. The females give birth to living young which remain under the parent scale covering for a short time. These young (the first instar nymphs) are known as crawlers. Crawlers move from the shelter of the female and migrate to the undersides of young twigs where they spend the winter. Once the crawler settles and begins to feed, it remains in the same spot for the remainder of its life. As the insect ages the exoskeleton hardens making it less susceptible to contact insecticides. In the spring two molts occur, one is usually in mid-May and the second in early June in New York State. The nymphs continue growing during July but at a slower rate, usually reaching maturity in August. There is one generation per year.
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One of the most important strategies in dealing with insects is to learn about them ñ which ones are pests, learn about the habitat they live in, their life cycle, what they will feed on and a little about the behavior. This information will help you decide what to do. Many insects found in the garden are not pests, and some will be beneficials.
Maintain vigorous, healthy plants - there is some evidence to suggest that plants growing under stressful conditions are more likely to be attacked and to suffer serious damage. Fertilization, liming, too little or too much water, and planting too close together can all adversely affect plants. Check the fertility and pH of soil regularly and make adjustments as needed. Thin plants to the recommended spacing.
Planting the same crop in the same place year after year may cause pest buildup. Rotate crops, especially where soil insects such as grubs, wireworms and maggots are a problem. Do not plant crops susceptible to grubs or wireworms where grass grew the previous year.
Choose recommended varieties for your area, and where available, resistant varieties to pests known to occur in your area. An example - butternut squash is listed as being resistant to the squash vine borer.
Sanitation in and around the garden is very important. Many vegetable pests overwinter in weeds or plant debris in or near the garden. Remove weeds and/or organic mulches which can provide ideal places for insects, slugs and snails to reside. Where mulches cannot be removed, at least collect and destroy the pests before setting out transplants or sowing seed.
Avoid bringing insect infested plants into the garden. Carefully check transplants for the presence of insects before purchasing and planting.
Consider time of planting - could the pest be avoided by earlier or later planting?
Hand-picking - removing the pest by taking them off the plants and destroying them. Insects may be killed by placing them in a bucket of soapy water.
Physical barriers placed around plants can control some insects. Included here would be such things as:
Cardboard collars (or roofing paper), four inches high, placed around young transplants to prevent cutworms from cutting the stems, and squares of tar paper or carpeting placed securely around the stems of young cabbage family crops to prevent the cabbage maggot fly from depositing eggs at the base of the plants.
Row covers placed over the plants until either the pest is gone or the plants are large enough to need the covers removed (all covers should be removed about four to six weeks into the season as temperatures during mid summer get too hot - remember some plants need to be insect pollinated or they will not yield a crop - cucumbers, melons, squash). There are commercial polypropylene, polyester and polyvinyl alcohol covers available, but cheesecloth or screening can also be used. All of these let in light and water and allow continued plant growth. Even ventilated plastic row covers help to keep out many pests.
Mulches - some research has shown that certain mulching materials such as aluminum foil may repel aphids, thrips and other insects. Although this material is expensive, it may be practical on the small scale.
Traps such as yellow sticky boards can be used to help monitor insect populations, but they are seldom sufficient to give control. They do help, however, to maintain whitefly populations at a low level as long as the sticky material is replaced periodically when insects cover the boards.
Biological control by the introduction of predators, parasites or diseases may become more practical as we learn more about managing the pest system. Remember when introducing or maintaining predators or parasites, if there are insufficient hosts for them to feed on, the beneficials will move elsewhere.
Pesticides may also be used as part of the pest management program. Be sure to use only the amount you need, and to treat only the crops that need treating. Spot treatments are effective and may be practical for home gardens. Before using any pesticide check the label - the crop you want to treat, and the pest you are treating for must both be listed on the label. If not, do not use the pesticide.
It is important to note that just because a pesticide may be botanical in origin, it does not mean that it is non-toxic. Some botanical insecticides are more toxic than some of the commonly available synthetic chemicals.
Biorational pesticides, such as Bacillus thuringiensis ( B.t.), a bacterium which attacks caterpillars, are an alternative to some chemical pesticides.
Insecticidal soaps are also an alternative to some chemical pesticides and may be useful for certain pests, especially aphids, in the home garden.
Diatomaceous earth, a desiccant is sometimes used for control of insects and slugs and snails. Once it gets wet and compacted, however, it loses effectiveness.
No matter which methods you choose, try to keep a record of what
you did and whether it was successful. Such a record should be a
great help in the future when you are faced with similar pest
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In late July many area residents become increasingly alarmed by a tiny leaf feeding insect attacking their maples. This insect is commonly called the maple trumpet skeletonizer. A tiny light green to cream colored caterpillar (larva) feeds on the lower leaf surface of maples. As it feeds it builds a long gray trumpet-like tube in which it hides and will later pupate. The adult stage is a small gray and black mottled moth.
DESCRIPTION AND LIFE HISTORY:
Most adult mealybugs are soft-bodied wingless insects about 5 mm (3/16 inch) in length. In a few species winged males may be present. The adults are an elongate-oval shape and often are whitish due to a waxy covering on the body. There may be two or more long waxy filaments extending from the posterior end of the body. Adults are found at rest or slowly crawling on the undersides of leaves or on stems.
Mature females deposit eggs in a loose cottony wax which may be
conspicuous on the stems and undersides of leaves. As many as 600
eggs may be in a mass, so the potential for populations to increase
is great. The newly hatched young crawl rapidly about for a few days
and may be carried from plant to plant by air currents. Young
mealybugs (nymphs) are yellow to pink in color, but as soon as
feeding starts, they begin to exude the white waxy material that soon
forms a covering over the body. As the mealybugs feed they excrete
honeydew, a sweet sticky substance that appears as shiny spots on the
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The Mexican bean beetle, formerly called the bean ladybird, is one of the most destructive insect pests of beans in New York State. The beetle feeds on the leaves of almost all types of beans including snap, lima, pinto, navy, kidney and soybeans. With snap beans, bush varieties seem to be attacked more readily than pole varieties.
Most of the damage from the Mexican bean beetle occurs during July and August. Both the adult and the larval stages feed on the foliage chewing out holes in the leaves. They usually feed on the undersides of the leaves, and sometimes will attack young pods and stems. As a result of the feeding, only the veins are left giving the leaves a lacy appearance. Yield may be greatly reduced and the entire planting may be destroyed in severe infestations.
The Mexican bean beetle is a convex beetle, about 1/3 inch long, and pale yellow to copper color with 16 black spots on its back. The beetles are pale yellow when they first emerge from the pupal stage, but as they age, they develop the typical copper color. The eggs are yellow and found in irregular clusters of 40 or more. The larvae are also yellow and have branched spines on their body giving them a fuzzy appearance.
The adult beetles overwinter in sheltered locations. They leave the overwintering sites when the weather warms up in mid-to-late spring. The females deposit their yellow eggs in clusters on the undersides of the bean leaves. In 5-14 days the young larvae hatch and begin to feed, passing through four molts before reaching the mature size of about 1/3 inch in 3 to 5 weeks. The mature larvae attach themselves to the undersides of the bean leaves and transform into the pupal stage. The pupal stage is the resting stage and does not feed. In 3 to 7 days the adult beetle emerges. In the fall when cold weather approaches, the adults migrate to sheltered areas in which they will spend the winter.
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Simply hearing noises or noticing disturbed food and shredded paper doesn't necessarily mean that you have mice in your home or building. There are, however, certain unmistakable signs that indicate the presence of mice.
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(In and Around the Home)
The house centipede is discussed separately.
Millipedes, sometimes called "thousand leggers", have elongate segmented worm-like bodies with short antennae and 2 pair of legs per body segment. They crawl slowly across the ground, and when disturbed, roll themselves into a coil. In New York State, those most often seen around the home are brownish in color, rounded in profile and about 1 to 1 1/2 inches in length. A few species which occur in wooded areas, however, may exceed 4 inches in length. A second more flattened form of millipede is not uncommon.
Sowbugs and pillbugs are oval dark gray, hard shelled arthropods with 7 pairs of legs. They reach about 1/2 inch in length. They too are found in moist places under debris or in damp soil where decaying vegetation is the usual food, but like millipedes, they can cause some damage to young plants. Pillbugs can roll up into a tight ball when disturbed; sowbugs do not roll up as tightly.
Centipedes (ìhundred-leggersî) are elongate, short-legged, flattened arthropods with 15 or more pairs of legs. There is one pair of legs per body segment and the antennae are prominent. When disturbed, centipedes often run for cover. Centipedes can deliver a somewhat painful, venomous bite and should be handled with appropriate care. These arthropods are not likely to infest houses unless conditions are quite moist and prey is abundant.
BIOLOGY AND LIFE HISTORY:
Centipedes, sowbugs, pillbugs and millipedes are primarily nocturnal, avoiding light.
Millipedes, sowbugs and pillbugs normally live outdoors where they feed on decaying vegetation. Occasionally they will attack the stems and roots of young plants, or they may feed on tubers or vegetables stored in cellars or basements. This, however, most frequently happens in the presence of previous damage.
Millipedes deposit eggs in clusters in the soil throughout the summer. Young hatch from the eggs and undergo a series of molts, during which the number of segments in increased. It often takes more than one year to reach sexual maturity. The females of sowbugs and pillbugs carry the young in a pouch on the underside of her body until the young leave the pouch. They may have 2 or more broods per year. Sowbugs often live to be 2 years old.
Centipedes are predaceous, feeding on insects, spiders and other small animals. They do not cause damage to plants.
(Scutigera coleoptrata (Linnaeus)
The house centipede differs from the above related arthropods in that it is fragile, gray to light brown, long legged and about 1 inch in length. It is the only common house infesting centipede. It is sometimes observed running across floors at great speed.
House centipedes prefer to live in moist areas, but they forage
actively at night and may be found in drier areas of the home as
well. They are predaceous, feeding on insects, spiders and other
small animals. They do not cause damage to plants.
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We are most concerned with these flies when they appear in our houses creating annoyance. Moth flies are also called filter flies, drain flies and sewage gnats. The larvae breed in moist organic matter and feed principally on algae. The muck of gelatinous material that accumulates on the sides of drains and overflow pipes in houses may provide suitable breeding sites. Some species are able to survive hot water and soap. Where they are a problem, the adults may be seen resting on walls in kitchens, bathrooms and basements. Usually only a few are present at any one time, some die off, and others emerge, but occasionally, they may occur in large numbers.
Moth flies are thickly haired, short, broad-bodied flies usually less than 5 mm (1/4 inch) in length. The wings are often clothed with hairs or scales giving the flies a ìfuzzyî appearance, and are held roof-like or tent-like over the body when at rest. They are not strong fliers and are often seen crawling over the walls or other surfaces. When they do fly, they cover only a few feet at a time and fly in a jerky line. The adults may be attracted to lights.
Out of doors, these flies are common in shady places in the vicinity of water, and they are often found in large numbers on dense foliage in swampland. These flies belong to the family Psychodidae.
The moth flies may go through the life cycle in 1 to 3 weeks and the adults can live for about 2 weeks after emerging. Eggs are laid in irregular masses in such places as water traps in plumbing fixtures, around built in sinks, garbage disposals, or anywhere decaying organic matter occurs. The larvae and pupae are aquatic or semi-aquatic, living in the decomposing film.
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The mountain ash sawfly can defoliate a tree in a short time when it is present in large numbers. The European and American mountain ash (Sorbus aucuparia and S. americana) are the known hosts. Damage can be seen in late June or early July. The larvae feed on the leaves and devour all but the mid-ribs and larger veins.
The adult sawfly resembles a stout wasp in appearance, and is yellow with black spots. Cocoons are tan to brown, oval in shape, and are found on the ground under the tree.
In late May or early June adult sawflies emerge from the overwintering cocoons and the females begin to lay eggs in slits cut into the leaf edges. The tiny larvae begin feeding as soon as they hatch from the eggs and increase gradually in size over the next three to four weeks. When the larvae are fully grown, they drop to the ground and spin cocoons. There is usually one generation per year, but at times, a partial second generation may occur. The larvae feed in groups starting on one or two branches, but soon moving on to others as the food source is depleted.
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Harmonia axyridis (Pallas)
The multicolored Asian lady beetle, Harmonia axyridis (Pallas), first
found in New York in Chemung County in early 1994, is an introduced
biological control agent that is spreading rapidly in the Empire
State and throughout New England. It has become a major nuisance to
homeowners because of its habit of invading houses and buildings in
large numbers in the fall (mid-October to early November and
appearing again on warm, sunny days in February and March. Despite
its annoyance value, H. axyridis preys upon many species of injurious
soft-bodied insects such as aphids, scales, and psyllids and is thus
considered beneficial to growers and agriculturists.
Although multicolored Asian lady beetleî is the common name officially accepted by the Entomological Society of America, several other common names are also found in the literature: halloween lady beetle (because of its pumpkin orange color and large populations often observed around Halloween), Japanese lady beetle (because Japan was the country of origin for specimens released in the southeastern United States), and Asian lady beetle.
The native range of H. axyridis encompasses much of Asia, including southern Siberia, Manchuria, Korea, China, Formosa and Japan. It was first released to control aphids on several agricultural crops in North America: in California in 1916, 1964, and 1965, and in Nova Scotia, Connecticut, Delaware, District of Columbia, Georgia, Louisiana, Maine, Maryland, Mississippi, Ohio, Pennsylvania, and Washington from 1978 to 1982. Despite these releases, there were no subsequent reports of recoveries or establishment of this exotic lady beetle. Then in 1988 in Louisiana and 1990 in Georgia and Mississippi, entomologists collected specimens of H. axyridis. Some researchers have suggested that these lady beetle populations in the South probably originated from an accidental introduction from Asian freighter activity at the port of New Orleans and not from intentional USDA releases. Since the early 1990s, this exotic lady beetle has proliferated and moved rapidly from the Deep South into the northeastern states and eastern Canada. It is now widely distributed across much of the United States east of the Mississippi River and is also found on the West Coast (California, Oregon and Washington).
Harmonia axyridis is a highly polymorphic (occurring in many color forms) species. Adults are strongly oval and convex, about º inch long and 3/16 inch wide. North American populations are comprised of co-occurring individuals that range in color from pale yellow-orange to bright red-orange, with or without black spots on the elytra, or wing covers. The head, antennae, and mouth parts are generally straw-yellow but are sometimes tinged with black. The pronotum is similarly straw-yellow with up to 5 black spots or with lateral spots usually joined to form 2 curved lines, an M-shaped mark, or a solid trapezoid. The wing covers are generally yellow-orange in unspotted individuals. In maculate (fully spotted) individuals, each wing cover has 10 black spots: a faint mark behind the scutellum, 2 spots at one-fifth, 3 spots in a semicircle at two-fifths, 3 spots at three-fifths and 1 spot at four-fifths. These black spots are variously reduced or even absent in some individuals.
Larvae are elongate, somewhat flattened, and adorned with strong tubercles and spines. The mature larva (or fourth instar) is strikingly colored. The overall ground color is mostly black to dark bluish-gray, with a prominent bright yellow-orange patch extending over the dorsolateral lobes of abdominal segments 1 to 5 on each side.
LIFE CYCLE AND HABITS:
During cool spring weather, development from egg to adult requires about 36 days or longer. Eggs generally hatch in 3 to 5 days. Larvae feed voraciously for about 12 to 14 days on aphids, scale insects, and other soft-bodied invertebrates. The pupal stage lasts about 5 to 6 days. After emergence, adults can live as long as 2 to 3 years under optimal conditions. It is believed that females overwinter unmated, with the majority of the population mating later in the spring.
In Japan, Harmonia axyridis is considered primarily an arboreal species and is common on various aphid-infested trees and bushes such as maple, walnut, willow, and rose; it is also an important predator of various destructive scales in Japan and mainland China. H. axyridis has also been closely associated with harmful aphids and scales on various nursery, ornamental, and field crops in North America, including Christmas trees, apple, alfalfa, wheat, cotton, tobacco, and small grains. The beetles have been released in Georgia (1978-81) and California and Texas (1994) to control pecan aphids and as a result have successfully reduced the use of insecticides by pecan growers. An adult beetle is capable of eating 90 to 270 aphids per day, and each larva can consume 600 to 1200 aphids during its development. In New York, these lady beetles have been prevalent on copper beech, honeysuckle, and European spindle tree heavily infested with aphids. Between 1983 and 1986, releases of H. axyridis were made in Connecticut for control of red pine scale (Matsucoccus resinosae) on red pine. In Pennsylvania, this predator has been observed feeding on the balsam twig aphid (Mindarus abietinus) and pine bark adelgid (Pineus strobi) in Christmas tree plantations and on aphid-infested apple, birch, cotoneaster, and rose.
The Cornell Department of Entomology and Cornell Cooperation Extension offices have received numerous inquiries about H. axyridis, primarily because of its annoying habit of invading houses and buildings in massive numbers. It does so during its search for protected overwintering sites in the fall and reappears on sunny, warm days in February and March. Although they are primarily beneficial insects, these colorful lady beetles can congregate by the hundreds or even thousands on outside surfaces as well as indoors on walls, doors, ceilings, and windows, becoming a great nuisance to home dwellers. The beetles seem to prefer light-colored (particularly white) houses located in open fields. This behavior relates to their natural tendency to fly to rock outcroppings in Asia while searching for overwintering sites. Indoors, the beetles commonly cluster together in a corner of the ceiling and wall. Homeowners may complain about beetles crunching under foot and crawling on their arms, hands, and legs. The beetles do not reproduce indoors, however, nor do they bit, sting, carry human diseases, or feed on wood, clothing, food, or houseplants. Growers and agriculturists consider these lady beetles to be biological control agents of the many different soft-bodied insect pests on a variety of crops, including ornamental trees and shrubs.
Despite complaints from homeowners, H. axyridis is a promising biological control agent of several insect pests on a wide variety of ornamental and agricultural crops. Its large, and even explosive, populations are probably caused by the massive abundance of prey (predominantly aphids and scales), apparent lack of competition from native lady beetles, and apparent lack of native natural enemies. Scientists predict that multicolored Asian lady beetle populations will become more balanced when its prey numbers decrease and Harmonia itself falls prey to native natural enemies. Overall, H. axyridis is a welcome addition to the fauna of New York, and it may help reduce farmersí reliance on insecticides to control aphids and other soft-bodied insects pests.
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