Leafworm is a large family of the order Lepidoptera, a widespread and dangerous pest of cultivated fruit and berry crops, grapes, forest and ornamental plantings. The lack of measures to protect plants from leaf rollers leads not only to the loss of most of the crop, but also to serious damage to the plants themselves.
- Species composition
- Life cycle and development of leaf rollers
- Harmfulness and risk factors
- Methods for controlling the number of leaf rollers
"Leaf roll" - the name was obtained due to the fact that the caterpillars of most types of leaf rolls roll the leaves of forage plants into bags or tubes.
The material considers the species composition of leaf rollers, their appearance, life cycle, developmental and nutritional characteristics, risk factors, methods of population control and recommended drugs, etc.
Leaf rollers are one of the largest families of the order Lepidoptera. There are about 10,000 species in the world, and about 2,500 species in Russia. The maximum diversity of species is observed in the mixed and deciduous forests of the northern hemisphere, in the subtropical and tropical forests of Asia.
About 100 species of leaf rollers are classified as serious pests of vines, berry, fruit and leguminous crops, as well as park and forestry. Among which are:
- Kidney leafworm (Spilonota ocellana),
- Willow leaf rollers (Pandemis heparana),
- Grape leafworm (Sparganothis pilleriana),
- Grape leafworm (Lobesia botrana),
- Biennial leafworm (Eupoecilia ambiguella),
- Frozen leafworm (Exapate congelatella),
- Currant currant leafworm (Pandemis ribeana),
- Fruit roll (Hedya nubiferana),
- Leafworm flat mesh (Acleris rhombana),
- Subcrustal leafworm (Enarmonia formosana),
- Rose leafworm (Archips rosana),
- Lead-striped leafworm (Ptycholoma lecheana),
- Reticulated leafworm (Adoxophyes reticulana),
- Bbw hawthorn leafworm (Archips crataegana)
and) BUTTERFLY... Butterflies up to 2.5 cm in size. Head with eyes. Antennae simple; proboscis short, coiled, sometimes underdeveloped. The wings at rest are folded roof-like, widen at the base, the length of the wings is 2–4 times their width. Pattern on fore wing of light bands or stripes on darker background. It can be colorful and bright.
b) CATERPILLAR... The larva (caterpillar) is worm-shaped with a semi-prognathic or prognathic head. On each side of the head capsule, 6 simple eyes are placed. Caterpillars of leafworm are 16-legged, almost naked, with sparse scattered hairs. In color - yellowish / pinkish-white or greenish.
in) EGG... The egg is flattened, round or oval with a transparent shell of a reticular structure.
d) PUPPET... Pupa of primitive type. Abdominal segments 4–6 in females and 4–7 in males are mobile. The main part of the abdominal tergites is equipped with two rows of sharp, caudally directed spines. With their help, the pupa is pushed out of the cocoon.
Life cycle and development of leaf rollers
Reproduction is bisexual. Development is complete. The wintering phase, the amount of generation and other biological indicators of development depend on the species and climate of the habitat.
Let us consider the life cycle using the example of a grape leaf roll. Flies in May, in the evenings or in the morning. Many species are attracted to light, especially to UV lamps. The daily rhythm of activity of adult insects is influenced by temperature, illumination, humidity and other natural and climatic factors.
Females are able to mate on the second - third day after leaving the pupae. After fertilization, they immediately start laying eggs. A grape roll lays on young shoots of vines up to 150 eggs. The fertility of the female in different species ranges from several tens to a thousand eggs. The caterpillar is about 1 cm long.
Pests of grapes - grape and bunchy leaf rollers
At the end of June it pupates in a cocoon in a folded leaf, or between the stalks, or under the bark and in the crevices of grape stamens. Two weeks later, new butterflies fly out and lay eggs on grape berries or their legs. Newly released caterpillars live inside berries, passing from one to another and throwing droppings out of them. Pupation occurs in feeding places, litter, surface layer of soil, crevices of tree bark, in a sparse silk net or in cocoons. Sometimes cocoons are quite strong and covered with plant debris or soil particles.
The pupa hibernates in a cocoon, covered with a thin layer of earth, being in a state of diapause, is frost-resistant and is able to withstand temperatures down to -40 ° C. They can winter in different stages depending on the species and habitat - it can be an egg, adults, caterpillars of the 1st or 2nd instars, feeding caterpillars of the last instar, pronymphs in cocoons, pupae.
The number of generations - in the middle lane, polycyclic species can develop annually in two generations, to the south - in three generations.
Leafworms find food in almost all parts of the plant, from flowers and flower buds to roots.
The larva (caterpillar) feeds on buds, flowers and young berries, braiding and pulling them into bundles with cobwebs, is also embedded in the stem of the shoot or brush, and then the latter dry out. The larva (caterpillar) of the first - second instars mine or gnaw out the buds, damage the blossoming leaves and buds, especially the tops of the shoots are affected. Caterpillars of older instars are mostly leaf-eating; they develop in leaf clumps, tubes, bundles, or between woven silk leaves.
Caterpillars pull together the cobwebs of the eaten leaves into tubes or bundles, inside which they hide (hence the name of the family). In a state of anxiety, they jump out and hang on cobwebs in the air.
Leafworms pull together the cobwebs of the eaten leaves into tubes and bunches
Harmfulness and risk factors
The family of leaf rollers includes a large number of species - pests of cultivated plants. The larvae are harmful. The vital activity of caterpillars leads to a decrease in the quantitative and qualitative indicators of the products of horticulture and field cultivation, and causes significant harm to the garden and park economy.
Methods for controlling the number of leaf rollers
1) AGROTECHNICAL - this is the use of agricultural practices aimed at reducing the number and harmfulness of caterpillars. Increasing plant resistance. Tillage, Glue traps and trapping belts, etc.
2) CHEMICAL method - timely spraying of plants during the growing season with chemical pesticides ("Bi-58 New", "Decis Profi", "Confidor", "Fufanon", "Calypso", "Alatar", "Lufox", "Aktellik", "Batrider" , "Avant", "Aliot", "Iskra", "Gerold", "Koragen", "Cypermethrin", "Prophylactin", etc.)
3) BIOLOGICAL - the use of biological products ("Bitoxibacillin", "Lepidocide", etc.)