Most people have seen the picture more than once when the apple tree and its branches are “wrapped” with cobwebs and, for sure, watching this, they thought that spiders wove the cobwebs on the apple tree. Of course, these insects can also weave it on any plant, but it will not be so thick and dense from spiders.
Web Source
The source of the web in the case when it is thick and dense is the caterpillars. This insect is a pest. It is called apple moth. Such a pest can appear everywhere, and the most important thing is to treat the plants on time, unfortunately, such a pest can ruin almost all the fruits of your plant. 
There is also a second type of pest – apple sucker. From it appears a white and very dense web throughout the plant. This insect is winged. Its larvae will suck juices from everywhere – from the buds, flowers and leaves of the tree. After that, it will secrete a specific, peculiar substance (excrement), which is very sticky to the touch and, outwardly, sugary. This substance glues the buds, leaves and buds together, from which mushrooms can appear on the apple tree. It is these mushrooms that are for our “eye” a white dense web.
In the photo at the end of the post you can see this web. In fact, if such a web appears on your apple tree, you urgently need to do something and take certain measures to destroy it and save your crop.
Such a web on an apple tree can also form in the winter season. Many gardeners are interested in what kind of cocoons, which are very clearly visible, hanging on the branches of their apple trees and what to do to get rid of them ?! These are also pests, they are called – hawthorn. They are small caterpillars that prefer to curl up and spend the entire period in their cocoons for the winter. If you have a hawthorn, you need to immediately process the plant in order to get rid of this pest as soon as possible.
How to fight
An apple tree is a fruit tree that not only creates a beautiful image in any garden, and at any time of the year, but also gives very tasty, healthy, vitamin-rich fruits. But if pests appear on the tree, they must be eliminated immediately. How to deal with them is described below.
With a cobweb that has formed on the branches of apple trees, it will not be difficult to fight, in general. The main thing is to detect the appearance of the cobweb in time, and start fighting.
It is also important that the gardener understands why the web appeared. If the apple tree began to be covered with a web in the form of a white mesh, in this case, an apple moth started up. To get rid of, you need: where you can get it yourself, reach out in places of the crown – remove the web with your hands. 
It is necessary to do the processing of apple trees at intervals of a week, and until you completely get rid of the cobwebs on the trees. You can also use a chemical preparation, which can also be purchased at specialized points of sale – Fitoverm, use it also according to the instructions in its packaging.
An important point is the mandatory removal and destruction of caterpillars, similar to small worms, as well as their nests, so that new pest larvae do not mature in the future. Leaves and branches that are located high must be treated with spraying. It is recommended to use a special, for this, infusion of tobacco. Also, you can buy biological products at specialized outlets, for example: entobacterin or dendrobatcillin, use these products – according to the instructions included in their packaging. 
For gardeners, there are also cases when it is not possible to process trees on time due to frequent and heavy precipitation in the form of rains. And then, instead of flowers, a lot of cobwebs will appear on the apple trees, with which the entire crown of the tree will be wrapped, and the leaves will be eaten by caterpillars, which look white with black dots – this is the ermine moth. A butterfly of its snow-white color, lays its eggs in small piles in cozy places on a tree, for example: branches, bases of buds. The eggs are laid in the form of shields. It is under them that the caterpillars hibernate. And when spring comes, they bite into the buds of the apple tree, and when the leaves bloom, the whole brood feed on the pulp of the leaves for two weeks.
Of course, after that the leaves will dry up, and the caterpillars will make a tent out of the web and will live in it (up to 70 pieces in one). Then they eat all the leaves on the tree, and the gardener did not have time to look back, as the apple tree had time to become covered with all white cobwebs. Then the caterpillars will pupate, butterflies will appear, which will again lay their eggs and everything in a circle …
It is best to inspect in the fall, you can even with a magnifying glass, young branches of an apple tree. If you find egg shields, they need to be scraped off well and burned. Also deal with dry branches, especially those that are heavily eaten. And before the frosts come, it is imperative to spray with lime milk, after which the apple tree should be covered with white.
Also, in early spring, be sure to cut and burn all the spider nests so that the caterpillars in no case crawl across your apple tree. Starting from the period when the apple tree is about to be covered with blossoming buds, and then with flowers, it is recommended to spray the trees. For example, you can use one of the recommended tools.
Video “How to get rid of cobwebs on an apple tree”
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