The ringed silkworm (cocoonworm) is a garden pest that is hard to miss. Caterpillars stuck to the branches of an apple, plum, pear, less often currants and gooseberries, literally swarm, and nests of cobwebs immediately catch the eye even of an inexperienced gardener. What to do? How to fight? After all, if you hesitate with control measures, then not only the harvest, the tree will die from the invasion of the pest.
Before fighting the ringed cocoon, you need to know the enemy by sight, namely, to have a good idea of what kind of pest it is, where it came from and how to defeat it not only for one season, but to minimize the possibility of re-infection.
Ringed cocoon moth (Malacosoma neustria L.) how to identify
During the life period, a ringed cocoonworm (lat. Malacosoma neustria L. Class Insecta, order Lepidoptera, family Lasiocampidae, genus Malacosoma.) Goes through several stages of development: egg, caterpillar, pupa, butterfly (imago).
The main color of the ringed cocoon moth butterfly (ringed silkworm) is from ocher yellow to brown. Male has comb antennae, in wingspan. Female is more powerful, large, in wingspan. Front wings are yellow-brown or reddish-brown in color with brownish light-bordered oblique transverse stripe. The fringe of the forewings is in irregular light and dark check. The hind wings are paler, without transverse stripes. The coloration of adult insects is highly variable.
Ringworm butterfly, adult (Malacosoma neustria adult). Photo: Wikipedia.org
Young caterpillars of ringed cocoon moth are black, about 2 mm long. Adult caterpillars are slender, the length , covered with sparse delicate hairs. The main color is gray-blue. On the blue-gray head and on the first two thoracic segments, there are two black spots. On the dorsal side there is a white longitudinal line, on the sides there are blue and red-yellow stripes, bordered in black below. Black spots and yellow spiracles are also characteristic.
Caterpillar of the ringed cocoonworm (silkworm). Photo: L. Bartolini Pupa of the annelid cocoon moth (silkworm). Source: Insecta.pro
The pupa of the annelid cocoon moth is brown to black, soft, covered with brown hairs, the length of the pupa is about 20 mm. Is in a lemon yellow cocoon of densely woven threads and, like the cocoons of other cocoons, covered with yellow-white pollen. Eggs are round, barrel-shaped, gray-brown, whitish on top, glued together with a solid substance in a ring.
What damages the ringed cocoonworm
Ringworm is a pest that loves warm weather, and even better if the tree is in the sun.
First of all, the ringed cocoon moth damages fruit trees: apple, plum, pear, but with a lack of fruit plantations, it easily and quickly passes to oak, birch, poplar and shrubs (for example, blackthorn).
In nature, ringed cocoon moth butterflies appear in June and July. During the day, butterflies sit on trunks, during mass reproduction on walls and fences with roof-like folded wings.
During the day, the cocoon moth butterflies are motionless, but at night they can be destroyed with electric traps.
The ringed cocoon moth butterflies fly in the evening. Larger and heavier females are less mobile, males fly swiftly, like other cocoons, and often fly to light sources... By the way, it is electric traps that are effective in the fight against the ringed cocoon moth, as a prophylaxis.
The female begins to lay eggs approximately in a week after mating. Females lay eggs in a ring around thin one- or two-year-old twigs. Sometimes the ring is incomplete, open or partial.
The eggs of the annular cocoonworm (silkworm) encircle the branch. Photo: J.J.Fito
One full ring contains which are tightly connected in rows. On average, the female lays about 300 eggs. Eggs overwinter in diapause.Caterpillars of the ringed cocoon moth hatch only next spring.
In April, May from the overwintered eggs of the annelid cocoon moth, caterpillars hatch within days, which immediately rise up into the crowns to the blossoming branches.
If the weather is cold and the opening of leaves is late, the caterpillars of the annelid cocoon wrap in dense cocoons, where they can lie numb for up to 6 weeks without food.
Caterpillars, falling on blossoming leaves or flowers, eat them forming between the twigs a nest of cobwebs... After prolonged feeding on warm sunny days without precipitation, caterpillars grow very intensively, crawl and eat leaves in the crowns.
Caterpillars of the annelid cocoon moth are characterized by "fluttering" movements of the front part of the body. Only in rainy weather and during molting do they crawl into the forks of branches or to the base of a branch near the trunk, where in a spider's nest they spend a short time without food and without movement.
Spider nest of ringed cocoonworm. In the nest of caterpillars, they rest from the labors of the righteous and wait out the bad weather. Photo: jjneal / livingwithinsects.wordpress.com
The entire period of development of caterpillars from the moment of hatching to pupation lasts ... Adult caterpillars pupate in June in yellow-white cocoons, most often in cracks in the bark or walls, sometimes among the already eaten leaves entangled in cobwebs, in exceptional cases on the ground in the forest floor. Sometimes several cocoons are joined together.
A new generation of ringed cocoon moth butterflies appears at the end of June, and most in July. The female lays eggs a short time after mating.
Ringworm is a pest that prefers a warm climate. Therefore, in the southern regions of Europe from time to time there are outbreaks of mass reproduction on relatively large areas of oak plantations, mainly in hornbeam-oak forests.
In damaged oak stands, these two caterpillars completely eat up the leaves, resulting in loss of growth and loss of seed yield. Disastrous outbreaks of mass reproduction, in which the ringed cocoonworm also has its share, lead to continuous devouring, and often to the death of oak plantations.
The ringed cocoonworm causes great harm in the northern regions of Russia, where outbreaks of mass reproduction also occur from time to time. Large areas of especially sparse deciduous forests, orchards and shelterbelts are being captured. In the Far East, mass reproduction occurs in low-lying elm forests with shrub undergrowth.
Polyphagous caterpillars damage all rosaceous fruit crops in gardens and parks, especially apple and plum trees, as well as forest species: oak, elm, birch, willow, etc., preferring oak... Discovered on black currant and raspberry, forced nutrition on soybeans and vegetables was noted: potatoes, cabbage, carrots.
If the apple tree has run out, the cocoonworm will take over currants and even potatoes. Photo: Wikimedia Commons
Since the middle of the year, the species has been observed on the territory of various districts of the Moscow region and adjacent districts of neighboring regions, where it is quite common, but nowhere is it numerous. Until recently, the species was also often found, sometimes in large quantities in forest parks, forest belts, gardens and squares in various districts of Moscow.
The ringed cocoonworm is widespread throughout Western Europe, Asia Minor, China, Korea, Japan, the Baltic States, Belarus, Ukraine, Moldova, Transcaucasia, northwestern Kazakhstan, Central Asia, the Urals, and also in the Crimea.
In Russia, the ringed cocoonworm is widespread in the European part, to the north to Petersburg-Yekaterinburg, in the south of Siberia and the Far East, including about. Sakhalin, about. Kunashir. For the Far East, a subspecies has been allocated M. testaceum Motsch... Also known as a pest in northern China, Korea and Japan.
How to deal with a ringed cocoon
It is difficult to fight a ringed cocoon, the easiest way is to prevent the development of caterpillars on infected trees by cutting and destroying branches with eggs. The easiest way is to burn the branches along with the eggs.
If ringed cocoon moth eggs are found in small numbers on young trees, they can be removed by washing off the clutch from the branches with an insecticide solution or water.
Young caterpillars of the ringed cocoon moth, with a small number, are destroyed by burning the cut branches along with the cocoons on them. Burning branches guarantees the death of caterpillars, moreover, the method is safe for human health. Cuts of branches must be covered with garden var.
The use of chemical preparations is justified with an average and high number of annelid cocoon moth caterpillars. Insecticide treatment is carried out before flowering and after flowering fruit trees.
- Alatar - 5 ml per 10 liters of water. Process by thoroughly wetting the leaves and branches of fruit trees. It is advisable to process the leaves on both sides. Frequency of processing - 3. Frequency of processing - 20 days.
- 1% solution of DNOC is treated in the spring, before bud break,
- Chlorophos solution is treated during the period of caterpillar emergence, preferably before flowering fruit trees.
- A mixture of 50 grams of entobacterin and 2 grams of chlorophos, dissolved in 10 liters of water, is used to treat large gardens.
In severely advanced cases, it is recommended to use cypermethrin solutionscommonly used to control ticks. After treatment with cypermethrin, it is not recommended to eat fruits and berries from the treated plants.
It should be remembered that the fight against the ringed cocoon should be regular and annual. Only a skillful combination of preventive measures and the destruction of all stages of the insect guarantees the health of your fruit trees and shrubs, and hence the harvest of fruits and berries.
How do you fight the ringed cocoon?