Harmful Hawthorn

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

The hawthorn, actively damaging various fruit crops, is most often found in the forest-steppe and woodlands. Her taste preferences include apple and pear, mountain ash, blackthorn, apricots with plums, bird cherry and, of course, hawthorn. But this scoundrel damages cherries with cherries to a much lesser extent. Caterpillars are especially harmful in the spring, mercilessly gnawing swelling and opening buds. As for the leaves, only coarse veins remain of them - all other parts of them are completely devoured by the pests

Meet the pest

The hawthorn is a rather interesting butterfly with a wingspan of 60 to 65 mm. The wings of females are distinguished by pronounced translucency - this is due to the fact that their scaly cover is rather weak. As for males, they lack scales exclusively along the periphery of the wings. The veins on the wings are black in males, and brown in females. All hawthorns are endowed with clavate antennae, and their dark abdomens and breasts are covered with light hairs.

Oblong hawthorn eggs are equipped with twelve to fourteen longitudinal ribs. All of them are colored orange or yellow and reach a height of 1.5 to 1.7 mm. Weakly hairy caterpillars, growing up to 45-50 mm in length, are endowed with brownish heads and black anal and thoracic segments. The bottom of the body and sides are grayish, and on the dorsal side you can see three black and two orange stripes. The size of white or yellowish angular pupae can be up to two centimeters. Each pupa is covered with black spots and dots. They are openly placed on trees, with their head ends up and attaching to the substrate with fancy spider web belts.

Caterpillars of the second and third centuries overwinter in winter nests built from dry leaves, which are attached to the branches with the help of spider web belts. Often, in one nest, from two to seven dozen caterpillars are comfortably located, while each individual is in a separate grayish round spider web cocoon.

When the average daily air temperature reaches seven to eight degrees, caterpillars begin to slowly leave their nests. Usually at this time the buds of the apple trees begin to swell. For the first few days, gluttonous parasites keep together not far from winter nests, which serve them as a reliable shelter from bad weather. And as soon as the thermometer rises to fourteen degrees and above, they slowly creep away and begin to lead an isolated lifestyle. If the weather is accompanied by frequent precipitation, and the air temperature drops below eleven degrees, the caterpillars will live together for the first week and a half after leaving the winter nests. As a rule, their development takes from twenty-seven to thirty-two days, and all this time the pests actively feed on buds, buds, leaves and flowers. And when the flowering of summer varieties of apple trees ends, caterpillars will begin to pupate on buildings, twigs and trunks, attaching themselves to them with strong spider web belts. The development of pupae usually takes from eleven to fifteen days.

The butterflies that have flown out drink water and feed on flower nectar. Sometimes they mate immediately after leaving, but most often the mating of pests occurs at the stage of additional feeding. Five to seven days after this, butterflies begin to lay eggs on the upper sides of the leaves in groups of twenty to one hundred pieces. The oviposition process lasts twenty to twenty-five days, and the total fertility of females reaches half a thousand eggs. After about one and a half to two weeks, slowly growing caterpillars revive, which skeletonize the leaves for fifteen to twenty-two days.

How to fight

In autumn and winter, it is necessary to collect winter nests of hawthorns and promptly destroy them. The autumn attraction of various insectivorous birds to the gardens will also serve well.

In the summer, when the years of butterflies begin, as well as in the years of mass reproduction of pests, flowering weeds growing near gardens and in the aisles are additionally destroyed. If this is not done, then they will begin to attract whole hordes of hawthorns. And if three or four nests of these gluttonous parasites are found on each tree before bud break, they proceed to treatments with insecticides or biological products.