Silver hole - butterfly, appearance similar to a cut dry branch. In gardens, silver holes are not at all welcome guests, as they are considered dangerous pests. Large populations of silver holes are capable of destroying a garden or a small forest.

The appearance of the hole is silvery

These butterflies are small in size - the wingspan does not exceed 0.5 centimeters. The color of the butterfly is silvery white. The head is yellow-brown, downy. On the wings there is a mark of the same color. These marks are similar to the moon, hence the name of the butterfly.

The butterfly is inconspicuous, and when it sits on a shoot, it resembles a dry twig, this color allows it to hide from birds.

Excellent disguise is available not only in an adult, but also in eggs. The eggs are small with a flat base. The bottom of the egg has a greenish color, and the top is light, so the eggs go unnoticed.

Caterpillars are dark brown in color. Yellow stripes run along the body. The body is divided into segments by bandages. There is a spot on the head yellow color. The head is large and glossy. The length of the body of the caterpillar of the silver hole reaches 35 millimeters. The body is hairy with dense bristles.

The pupa has 4 processes below. The length of the pupa is approximately the same as the body size of an adult butterfly - 50 millimeters.

The harm caused by the silver hole

These butterflies feed on deciduous plants, preferring birch, oak and fruit trees. Pests settle in forests and parks. They intensively eat foliage, which can provoke the death of trees. Silver holes attack trees from June to September.

Reproduction of silver holes

Silvery holes appear on trees in early summer and make masonry. The female attaches the eggs to the back of the leaf. The fecundity of one female is approximately 50 eggs, but there may be more eggs in the clutch.

Malicious caterpillars hatch from the eggs after 2 weeks. They have a yellow color, black dots are located on the body. Young caterpillars cannot eat whole leaves, so skeletons remain from the leaves. Adult caterpillars are able to destroy the leaves completely.

The caterpillar lives for about 50 days, after which it pupates. To turn into a chrysalis, the caterpillar crawls down from the tree and pupates in the ground, at a depth of about 5 centimeters. In the ground, pupae can develop from 1 to 3 years. At the end of the development process, butterflies are selected from the ground.

• Class: Insecta = Insects
• Order: Lepidoptera = Lepidoptera, butterflies
• Family: Notodontidae Stephens, 1829 = Corydalis
• Genus: Phalera Hϋbner, 1819 = Holes

Species: Phalera bucephala (Linnaeus, 1758) = Silver hole, or knotty Falera

The hole is silvery, or knot-shaped Falera has wings with a span of about 50-60 mm. The anterior wings of the silver hole are painted in silver-gray tones and on them in the anterior corner there is a large, clearly visible rounded yellow spot. The hind wings are light, white-yellow in color with brown veins.

Butterfly breasts are covered with tufts of yellow-brown or red-brown hairs. The first segment of the abdomen is also covered with hairs. The abdomen has a main color background - silver-brown-yellow, and dark spots are located on its sides. The antennae of the male are short-feathery, in contrast to the small bristle-shaped antennae of the female.

Silver hole butterflies appear in nature from pupae, depending on location and weather conditions, at the end of May - in June. The years of imago are quite extended and usually last until August. During this time, the female can lay up to 250 eggs. The female lays fertilized eggs on the underside of the leaves in groups of 15-40 eggs in one layer. Each egg laid is 0.8-0.9 mm in size with a flat base. Its lower half is dark green, while the upper half of the egg is light, with a dark dot in the middle.

Duration embryonic development is 12-15 days. Most of the young caterpillars hatch in June. At first, they live all together under the protection of delicate fibers and skeletonize the leaves on which they hatch. Caterpillars of older ages gradually spread along the crown of a tree and begin an individual life, constantly feeding, eating leaves on trees. Adult caterpillars often concentrate in ramifications at the ends of branches, which are completely devoid of leaves.

An adult caterpillar can have a body color from dark to black-brown. Her entire body is covered with yellow hairs. Each segment has yellow longitudinal stripes and small yellow transverse stripes. The maximum body length of an adult caterpillar can be up to 60 mm. For 40-45 days of development, the caterpillars go through five instars, i.e. sheds four times, replacing their old tight clothes with a new one.

Caterpillars of the silver hole feed on the leaves of most hardwoods. They can damage tree crops such as: oak, linden, birch, aspen, mountain ash, alder, as well as beech, hornbeam, maple, walnut, willow, poplar and different kinds fruit trees. Foliage damage is easily detected by bare branches on trees, on which caterpillars of the silver hole live en masse. Even if the damage is sometimes significant and noticeable, the hole has no economic value.

After feeding, before pupation, the caterpillars descend from the tree, penetrate shallowly into the soil. Here the caterpillar turns into a semi-free, dark brown shiny chrysalis, 30-40 mm long, with delicate yellowish transverse lines. The appearance of the pupa is characterized by the presence of two complex points with outgrowths at the ends of their abdominal segments. The cremaster is flat, divided into two parts, which, in turn, are also bifurcated. Pupae overwinter in the soil without a cocoon, sometimes they can fall into diapause for up to two years.

Thus, the generation near the silver hole is one-year. The silver hole is common throughout Europe, where it is a common species, with the exception of the north. But in the steppe zone, in the Caucasus and Transcaucasia and the forest-steppe part Western Siberia often gives outbreaks of mass reproduction. Most often it can be found in forests, parks, gardens, it is common in cities where it lives and on hedges.

The silver hole is a pretty silver-white butterfly of relatively small size - its wingspan is only 0.5 mm. The fluffy heads of voracious pests are painted in yellow-brown tones, and on the back of their wings you can see small marks of similar shades. These patterns resemble the shape of the moon, which led to the name of harmful butterflies. A bizarre color helps the villains disguise themselves as broken twigs. A silvery hole sitting on a shoot can easily be confused with a broken branch - this helps pests protect themselves from various insectivorous birds.

Small yellowish stripes pass along the bodies of dark brown caterpillars of the silver hole, and all segments of their bodies are separated by tiny bands. And on the large glossy heads of pests there are funny yellow spots. All caterpillars are rather hairy, covered with dense bristles and grow up to 35 mm in length. As for the size of the pupae, it is almost equal to the dimensions of adult butterflies and is about 50 mm. The pupae are characterized by a brownish color and have four miniature processes below.

How to fight

If there are not very many harmful caterpillars on the trees, they can be collected by hand and immediately destroyed. Truth, effective way struggle this measure can not be called. DDT and HCCH dust treatments give a much better effect - as a rule, they are carried out on very large areas. And in small gardens, fruit trees can be treated with a twenty percent solution of HCCH, DDT or CMME. In addition, trees are allowed to be sprayed with Metaphos, Chlorophos and some other organophosphorus preparations.

There are many silvery and natural enemies near the hole. The main enemies of these pests are Trichogramma egg-eaters. Pupae are often eaten by various rodents, including mice. In addition, sometimes pupae die from fungal diseases. But the pest caterpillars are so well protected that even birds are not interested in them.

The silver hole is a beautiful butterfly for the collection, which looks like a dry cut branch and will look great under glass, but only amateurs can show such interest in it. But in the gardens, she is far from being a welcome guest.

The fact is that the silver hole is dangerous pest, whose population is capable of quickly destroying forest plantations or your garden. In the article we will talk about this insect, its lifestyle, as well as how to drive the silver hole out of your garden.

What does a pest look like?

adult

The silver hole is a small butterfly. Its wingspan is only 0.5 cm, the butterfly itself is silver-white. Her head is fluffy, yellow-brown, on the wings there is the same mark on the back. These marks resemble the moon, which is why the butterfly has such a name.

Thanks to this color, the butterfly disguises itself as broken branches. When a silvery hole sits on a shoot, it can be confused with a broken branch, which allows it to defend itself against insectivorous birds.

Good disguise is not only the butterfly itself, but also its masonry. The eggs that this insect lays are small and have a flat base. The egg is multi-colored, its lower part is the color of grass, and the upper one is light, which allows the masonry to go unnoticed by most lovers of it.

Caterpillar

The caterpillars of the hole are silvery dark brown, have yellow stripes along the body. Body segments are divided by bandages. There is a yellow spot on the caterpillar's head. The head itself is large and glossy.

How to deal with a pest?

The caterpillar is well protected, so it is rarely of interest to birds. The main enemy of the silver hole is the trichogram egg-eater. Pupae can die from fungal diseases. Sometimes mice and other rodents feast on them.

If there are few caterpillars on the tree, they can be collected by hand and destroyed. However, this is not the most efficient way.

Spraying with DDT and HCCH will help get rid of this insect. Since this preparation requires 15 kg per 1 ha, it is most often sprayed with the help of aviation. At home, the affected tree can be sprayed with CMME, DDT, or HCCH; the solution should be 20 percent.

Do not take the trichogram with your hands. Place crushed leaves in bags. In a few hours, the insects themselves will crawl onto them. Leaves with a trichogram should be spread out where the pest butterfly is found. Trichogramma will find her masonry by herself.

If a weather do not allow the release of insects, they can be stored in a cool room, the temperature of which is about +4 Celsius. You can’t wait more than two days - they will die. Do not place Trichogramma packets in the sun. The insect should be released carefully, as it can be damaged. With good resettlement, the trichogram will quickly destroy all the masonry of the pest butterfly.

Butterfly with a wingspan of 50-60 mm. The forewings are silver grey.

In the outer corner of each wing there is a moon-shaped golden-yellow spot, bordered on the inner side by an arched double dark line. The hindwings are white, with a slight grayish tinge.

The egg is hemispherical with a flat base. The lower half of the egg is dark green, the upper half is light, with a dark dot in the middle.

The caterpillar is dark brown with 10 discontinuous yellow longitudinal stripes and yellow transverse bands on each segment. The head is black, shiny, large, with a characteristic sign in the form of a yellowish fork. The caterpillar is covered with thin yellowish-gray hairs, 30-35 mm long.

The pupa is dark brown, shiny. The cremaster terminates in four fan-shaped processes. Length 30-50 mm.

Distributed throughout the European part of the USSR, the Caucasus, Siberia and the Far East.

Flight in June. Individual specimens are found from late May to August. The female lays her eggs on the underside of the leaves in a single layer, placing them closer to the edge of the apical part of the leaf. The clutch contains 40-60 eggs; sometimes it contains from 10 to 120 eggs. After 12-15 days, light yellow caterpillars with black dots, covered with hairs, emerge from the eggs. Caterpillars in the first two ages live in societies and only skeletonize the leaves, and starting from the third age they eat them whole. Caterpillars have five instars and live 40-50 days. During this time, one caterpillar eats 10-11 g of foliage.

Caterpillars are polyphagous, but prefer oak, linden, birch and poplar.

In September, caterpillars pupate in the soil at a depth of up to 5 cm, some of them deepen by 10-15 cm.

The pupa hibernates. One-year generation. Part of the pupae (10-15%) lie in the soil for another year and, if they do not die, the butterflies fly out only in the third calendar year.

Lunka is a typical inhabitant of the ravine forests of the southeast, found in young cultures and forest belts steppe zone, is widespread on poplar plantations, in nurseries and urban plantations of various landscape and geographical zones, as well as in mountain oak forests of the Caucasus (D. I. Lozovoi, 1952). It forms predominantly local foci.

In fluctuations in the number of holes, an important role is played by the egg-eater Trichogramma. Other entomophages are not significant. Birds of caterpillars almost do not touch. The attenuation of outbreaks is most often the result of diapause of pupae and their mass infection with fungal diseases and death from physical factors.

Supervision of the reproduction of the hole is carried out by pupae and is somewhat complicated by the presence of diapause in them. Therefore, it is additionally necessary to carry out control catching of butterflies for ultraviolet light.

On plantations and nurseries, with a small number of caterpillars, they can be collected by hand, and in denser foci on large areas carry out aviation dusting with dusts of DDT and HCCH (15 kg/ha) or spraying with 3-5% (according to the preparation) solutions of 20% CMME DDT or HCCH. Aerosols can be used, as well as ground dusting and spraying.

Caterpillars of the hole in the first ages are not very resistant to contact drugs and the chemical method gives excellent results.

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