Black Grape Beetle - Pest Control

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

Black grape beetle is especially harmful mainly in the south. Most often, grapes suffer from its vigorous activity, and a little less often - berry bushes with fruit trees. In general, this parasite, figuratively eating delicate leaves, is noted on eighty-five species of plants, therefore, having seen it on the site, you should immediately begin to fight it

Meet the pest

The black grape beetle is a beetle ranging in size from 8 to 11 mm. From above, it is painted black, and its rostrum is thick and short. Convex elytra of the parasite are equipped with longitudinal small grooves, between which there are gaps in wavy transverse wrinkles. Due to the lack of lower wings of these admirers of grapes, these bugs do not fly. All males have a narrower body than females, and the hind thighs are very decently expanded to the very tops.

Reaching 0, 6 - 0, 7 mm in length, the eggs of pests have an oval shape and a yellowish-brownish color. Light yellow wrinkled larvae up to 10 - 12 mm in length, arcuate, endowed with a brownish head and covered with sparse stiff hairs. And the little white pupae, the length of which is about 10 - 11 mm, are endowed with a pair of spines at the tops of the abdomen.

The harmful larvae that have not completed their development spend the winter together with immature beetles under the remnants of vegetation, as well as in the soil. Approximately in April, when the average daily temperature reaches 10 - 12 degrees, they begin to slowly get out of their wintering places, in addition to grape buds, additionally feeding on leaves of rowan, rose, apple and almond. In just one night, in fairly warm weather, each beetle is capable of destroying from five to seven buds. And as soon as grape leaves appear, the parasites feed mainly on them until late autumn. The lifestyle of these pests is predominantly nocturnal - during the day they hide.

After leaving the wintering grounds, after about 3 - 6 days, the gluttonous parasites begin to mate. They do this throughout the summer season. In late May and early June, these garden pests begin to lay eggs. The egg-laying process will last until September. They lay eggs almost always to a depth of ten to eighteen centimeters in the soil, in small groups or one at a time. 10-12 days later, the larvae revive, initially feeding on the remains of vegetation and even humus, and later moving to the roots of the vine. Depending on the moisture content of the soil, the depth of habitation of these larvae can vary from ten to thirty centimeters. If the soil is dry, they can be located a little deeper. All the larvae pass for seven centuries and during this period they have time to shed as many as six times.

Individuals reborn in late May or early June manage to complete their development by pupation. And the larvae that hatched later are in the soil until the spring of next year. Pupae development takes from eleven to sixteen days on average. The released beetles join the adults, additionally feeding on the leaves and laying eggs in 20-25 days. The larvae revived from such eggs overwinter in the soil. And as soon as the average daily temperature reaches ten degrees with the onset of October, the beetles will also go for the winter. These parasites live on average for two to three years, managing to lay up to one and a half thousand eggs during this time.

How to fight

Such predators as birds, lizards with frogs, as well as rather large ground beetles can significantly reduce the number of black grape beetles. And the ants do not mind eating the eggs of these parasites.

Cultivation of the soil in spring, summer and autumn will do a good job. If there are more than two or three larvae per square meter, various insecticides are introduced into the soil. And if for each bush there are three or more beetles, then two whole insecticide treatments are carried out: first - during the period of bud swelling and their blooming, and then - during the period of mass release of beetles. For treatments, such preparations as Chlorofos, Cydial and Rogor are suitable. And after budding, treatments with "Fozalon" and "Karbofos" are allowed.