Starting to talk about cabbage pests, one immediately remembers all the variegated caterpillars and colorful butterflies that are well known to every gardener. And somehow, at the same time, another, no less formidable pest of cabbage, a tiny cabbage aphid, is completely forgotten.
These very small sucking insects colonize leaves and shoots from early spring to late autumn in large groups (colonies). In each such colony there are wingless and winged females that fly over and infect other plants over large areas, since they have an almost incredible reproduction rate. It is estimated that the offspring of just one aphid per year can reach an astronomical figure, if they did not have a great many natural enemies.
And although the insect itself, a person with insufficiently sharp eyesight may not notice at all, the plants affected by the pest are very easy to identify.
The first sign of aphids on plants is garden ants scurrying through the leaves. Ants are "hard workers", not "bums", and therefore will not just run back and forth. This is the first sign of aphids on the plant. The ants carry aphids from infected plants to healthy plants and feed on the sweet sap secreted by the aphids.
Cabbage aphid is a small (2–2.5 mm), inactive, wingless, sucking green pest. Eggs laid in autumn overwinter on weeds and cabbage stumps. During spring, the cabbage aphid develops on the same plants on which the eggs hibernated. And in late May - early June, winged females appear, which fly to cabbage and other cabbage plants, where they give birth to larvae.
Aphids mainly inhabit the underside of the leaves. Adult aphids and their larvae pierce the skin of the leaves with their proboscis and suck out the sap from the plants. At the same time, the growth of the head of cabbage stops, the leaves are deformed, acquiring the shape of a dome, become colorless, curl and dry up, stopping the growth of the head. With severe damage, sticky discharge appears on them.
Over the summer, aphids give many generations. Mid-late and late varieties of cabbage suffer most from aphids. Aphids reproduce especially quickly in warm weather, and heavy rainfall and cool weather restrain the growth of the aphid population, and sometimes cause its death.
At the same time, plant protection from aphids is rather difficult, since it settles on the underside of the leaves. But this must be done constantly, using, first of all, various preventive measures.
First of all, next to the cabbage, it is necessary to plant at least a few tomato bushes, preferably low standard varieties, so that they do not shade the cabbage. Their smell scares off aphids.
It is very effective to use predatory insects against cabbage aphids (ladybirds, lacewings, etc.). But at the same time, it is necessary to refrain from chemical measures to combat aphids, and somewhere nearby to plant small clumps of seed plants of umbrella crops (dill, carrots, celery), attracting these insects.
In addition to preventive measures, it is necessary to constantly carry out "punitive" measures. When the first colonies of cabbage aphids appear with an interval of 12-15 days, it is necessary to spray the cabbage with infusions or decoctions from the tops of potatoes or tomatoes, onion husks, tobacco, etc., adding 40 g of soap per 10 liters of working solution. It is better to spray the affected plants in the evening.
If there are a lot of aphids on the cabbage and it is not possible to cope with it with the usual means, then it is necessary to spray the plants on the underside of the leaves with the preparations Iskra, Kinmix, Biorin, Fury, Zeta, etc. no later than less than 4 weeks before the start of the harvest.
Good results are obtained by pollination of plants with 2.5% Vofatox (metaphos) dust. This is explained by the fact that the body of the cabbage aphid has a fairly abundant waxy coating.Thanks to this, Vofatox dust adheres well and holds, and the liquid (solution of drugs) - on the contrary. In addition, when pollinating the plants are covered with poison more evenly than when spraying, a certain amount of dust gets on the underside of the leaves, where there are also aphid colonies.
The natural enemies of aphids are the larvae of sirfid flies, ladybugs, their larvae, as well as the larvae of lacewings. Of the parasites, the most useful in the fight against aphids is the aphidius wasp, which lays eggs in female aphids. Such a female swells in a spherical manner, acquires a brown color and dies. The wasp larvae fly out through a hole that they gnaw on the dorsal or lateral wall of the aphid's abdomen.
And after harvesting cabbage, it is imperative to carefully collect cabbage stumps, torn leaves and weeds on cabbage beds, immediately burn them or lay them in compost heaps. This will largely eliminate the overwintering eggs of the pest.
"Ural gardener", No. 13, 2020
