Leaf rollers are a family of butterflies. Leaf rollers cause harm not only to fruit trees, they have adapted to various living conditions and have mastered a variety of wild shrubs and trees. For example, several types of leaf rollers damage conifers exclusively.
The caterpillars of leaf rollers eat young shoots and leaves, as a result of which the tree does not grow and loses fruit. Caterpillars fold leaves into tubes with the help of cobwebs, in such shelters they pupate, hence the name of the family. Caterpillars of these butterflies, in addition to leaves and shoots, feast on flowers, buds and buds.
External features of leaf rollers
A distinctive feature of leaf rollers, which makes it possible to unmistakably recognize these butterflies, is a thick body with thick hairs and wide wings.
In moments of rest, the butterfly folds its wings in the form of a roof. Most species of leaf rollers have a pattern on their wings.
Leafworms (Tortricidae or Olethreutidae).
Caterpillars of these butterflies, unlike adults, are practically not covered with hairs; sparse hairs are present only on black convex points. Caterpillars have 16 legs. The body color is from yellow to green, and the head is black or brown. Pupae of leaf rollers have one feature: they have hooks on their abdomens.
What description
The tracks are almost completely smooth. There are single villi. The insect has 16 legs. The head is brown or completely black. The body has a standard hue - yellowish or green.
The pest can be characterized by the following features:
- antennae bristly;
- a shortened proboscis, which is underdeveloped, but the tentacles are absent;
- jaw tentacles three-segmented.
At rest, the wings resemble a roof. The upper ones are usually longer than the lower ones. At the base, they can expand.
Caterpillars are often found in higher elevations. The occipital and supra-tail scutes are present. Leafworms consume leaves from different plants. Damaged leaves are pulled together by a cobweb and twisted. It is there that the pest is located. In case of danger, the insect instantly gets out.
Caterpillars of this butterfly are small feed on foliage.
The larvae appear in early spring. Caterpillars are worm-like. The body length does not exceed 2 cm. The pest moves quickly due to the presence of 8 pairs of legs. In a short time, the parasite can bypass the entire garden and cause damage to many plants.
The caterpillar has 12 eyes - 6 on each side. The spinning iron is present, which is involved in the creation of the cocoon. The larvae often eat the buds, sprouts, and buds. The damaged plant is not capable of further maturation.
Brown leaf roll
The color of the brown leafworm is gray-brown, on the front wings there is a characteristic dark brown pattern with a clearly visible ocher edging. Females are brighter than males. Brown leaf rollers are numerous in Europe and throughout Russia.
Brown leafworms fly in June and lasts about 2 weeks. In the daytime, butterflies prefer to be under the shelter of a forage tree, and at dusk they begin to fly.
The leaf roll caused the famous ravages of the Champagne vineyards in the 1960s.
Mating takes place at night. Females also lay eggs at night. They arrange eggs in groups on the root of the trunk. One female makes 2-3 clutches, while the total number of eggs reaches 70 pieces. Females wrap their clutches in a rapidly hardening white substance that helps them withstand the cold.
In April, caterpillars of brown leaf rollers appear. An adult caterpillar reaches 20-24 millimeters in length. The body color is black, the head is black and shiny. Initially, the caterpillars eat the buds and blossoming leaves, while entangling them with cobwebs. In a twisted sheet, the caterpillar makes a refuge, in which it transforms into a pupa. The caterpillar stage takes 20-40 days on average.
Leaf rollers are ubiquitous, but most harmful in southern gardens.
The pupa of a brown leafworm reaches about 14 millimeters in length. The pupa is dark in color. There are 8 hooks in the tail section. The pupa development process takes 10-15 days. Brown leaf rollers are polyphagous insects, so they damage not only fruit trees.
Prophylaxis
Important methods of preventing apple leafworm:
- In early spring, as well as in autumn, clean tree trunks with a stiff brush from loose parts, moss, lichen, etc.
- Treat the trunks with a solution of chalk or lime.
- Cracks and damage on the trunks should be cleaned and treated with a 1% solution of copper sulfate, then covered with garden varnish.
- Remove fallen leaves and fruits not only in autumn, but throughout the season, as caterpillars and egg-laying can be found in them.
- Dig in trees.
- Remove curled foliage, prune dry branches.
Spruce bast leafworm
This type of leaf rollers prefers spruce young trees. They are most often found on solitary trees in the outskirts or on weakened trees.
Caterpillars of spruce bark-eating leaf rollers live under the bark, make various moves in it, thereby disrupting growth, causing deformation of the shoots and even provoking the death of trees.
For orchards, leafworms are becoming a particularly dangerous threat, eating whole fruit trees.
Butterflies of this type of leaf rollers have wide, but short wings. The color of the forewings is olive brown with sinuous light spots. They have transverse stripes and white fringes. The hindwings are paler, red-brown or gray-brown in color. They are also framed with a white stripe.
The emergence of spruce bark beetles begins at the end of May. Females make clutches under the bark scales. In June, caterpillars appear from them, which grow up to 11 millimeters in length. The body of caterpillars is most often whitish with a pink tinge, the head, thoracic legs and shields on the back and abdomen are yellowish-brown. The caterpillar develops until next year. After she pupates.
Preventive measures
Flower beetle on an apple tree: how to fight
Preventive measures to protect against leaf rollers are to follow the rules for caring for an apple orchard:
- Timely cleaning of the near-trunk circle from dry leaves and branches with their subsequent burning;
- Carrying out sanitary pruning, loosening and weeding of the soil;
- Carrying out formative pruning in order to exclude thickening of the crown. Normal branching of the apple tree not only protects against insects and diseases, but also has a beneficial effect on productivity;
- After autumn leaf fall, it is necessary to carry out hygienic cleaning of the bark. A stiff brush is used to brush off the dry layer of bark that forms crevices. This procedure also makes it possible to destroy the clutches already formed in the bark;
- The trunk must be whitewashed in autumn.
The leafworm is a dangerous and annoying insect that can return over and over again. Therefore, it is important to constantly monitor the apple trees, inspect and follow the cultivation techniques. Any disease is easier to prevent than to cure.
Spruce cone leaf roll
In a butterfly of this species, the wingspan is an eye of 16 millimeters. The upper pair of wings is dark brown with a metallic sheen and sinuous light stripes, while the hindwings are gray-brown. The wings are edged with a white fringe.
The caterpillar of the pine cone is white with a yellowish tinge, and the head is brown. Adult caterpillars reach 11 millimeters in length. The pupa is light brown in color and is 8 millimeters long.
It is most effective to carry out prophylaxis against leaf rollers in the spring, but not in the summer.
In our country, these butterflies are found in spruce forests. Leafworms of this type damage spruce cones. Females lay eggs between the cone scales. If the yield of spruce trees is low, then up to 10 caterpillars can live on one cone. For about 20 days, the caterpillar feeds on the scales of the cone, and then penetrates the core and begins to eat the seeds.
It is not easy to understand that the bump is infected. Infected bumps do not curl as they contain caterpillar waste and drill meal. Caterpillars pupate next year, in spring.
Treating the garden with chemicals
Chemical measures to control the leaf roll are considered to be the most effective. However, when working with them, it is important to strictly follow the instructions in the instructions and change the drug from time to time, since the pest can develop resistance. In addition, such processing is recommended for those cases where there are many parasites - more than five caterpillars on one branch.
So, in this case, you can use two types of insecticides: contact and systemic. The former are less toxic, but they do not always give the expected result. The latter are more aggressive, but their effectiveness is several times higher, even if there are a lot of pests.
With a slight infestation of the garden, the following drugs are usually used against the leafworm:
- "Alatar";
- Fufanon;
- "Karbofos";
- Dursban;
- "Atom";
- Ditox;
- Actellik.
If the infection is total, then in this case you cannot do without the help of synthetic pyrethroids and powerful insecticides:
- Ivanhoe;
- "Chord";
- Kinmix;
- Inta-vir;
- Alfatsin;
- "Fastak";
- Fury;
- Rovikurt;
- "Fatrin".
Important! Pyrethroid drugs are used at temperatures no higher than + 23 ° C. With higher thermometer readings, these tools do not work. And it is advisable to use them only as a last resort, when other measures were ineffective!
If we talk about the methods of combating the grape bunch of grapes, then the treatment of this type of pest should be started already in February. At the end of winter, shoots and supports must be abundantly moistened with Nitrafen working solution. The second treatment is carried out during the growing season, using one of the above preparations, and the third - no later than 30 days before harvest. It will be biological or chemical insecticide - you decide, here it is desirable to build on the intensity of the infection.
Larch roll
Leafworms of this species live in the coniferous forests of Russia, Europe and America. The front wings of the butterfly are narrow, most often they are gray with a pattern of stripes, strokes and dark brown spots. The lower wings are wide and brown. Both the upper and lower wings are bordered by a gray stripe.
More than 50 species of leaf rollers live in our country.
Pupa of light-root color. Caterpillars of larch leaf rollers reach 8-10 millimeters in length. The body color is dark green. Females lay their eggs on coniferous trees, in cracks in the bark. The caterpillars that emerged from the eggs feed on the needles. They pull together the needles with a web, forming a cocoon of them. Adult caterpillars are already moving to young shoots. To turn into a pupa, a caterpillar descends on a cobweb to the foot of a tree, makes a cocoon on the ground from fallen needles, and after 14 days a butterfly emerges from it.
The reasons for the appearance of the pest
The pest wakes up in the spring with the arrival of heat, as soon as the air warms up to 10 ° C. The optimal conditions for insect reproduction are humidity and air temperature in the range of 20-24 ° C. Cold and rainy weather inhibits the reproduction of leaf rollers.
Caterpillars often enter the garden with the wind. On the infected trees of the neighboring area, he picks up young larvae hanging on thin cobwebs and transfers them from one tree to another. At risk are trees and shrubs growing next to a neighboring abandoned and unkempt garden or near a forest.
Spruce needle-eater
In this species of leafworms, the front pair of wings is wide, dark brown, with silvery stripes and spots. The second wings are narrower in shape, their color is light brown. The wings have a gray edging.
The caterpillars of the spruce needleworm are greenish in color with gray longitudinal stripes, or they may have a yellow color with brown stripes. The pupa is brown; there are hooks in the caudal part of its body.
As a rule, leaf rollers inhabit healthy or only slightly weakened trees.
The female lays eggs with needles. Initially, the caterpillar lives on the surface of the needle, and then makes a hole in it and penetrates inside, starting to gnaw it from the inside. The needle falls off, and the caterpillar pupates in the forest floor.
These pests attack conifers that are 10-30 years old. But if there is not enough food, then they take a fancy to younger plantings.
Controlling the parasite with biological insecticides
Biologically active agents are capable of destroying the leaf roll, the advantage of which over powerful chemicals is that they can be used at any stage of plant development. They are absolutely safe for insects that take part in pollination, and do not accumulate either in the soil, or in the fruits, or in the body of the plant itself. Thus, treatment with these preparations is possible both during the flowering period and immediately before harvesting.
Quite good results in the fight against leafworm caterpillars on fruit trees and berry bushes are shown by such means as:
- "Lepidocide";
- "Bitoxibacillin";
- Dendrobacillin.
