Weevil: how to get rid of and fight the pest

Weevil beetle (lat. Curcullionidae), or elephant beetle, belongs to one of the largest families, which has more than 70,000 species. The long-nosed beetle is a pest of plants, and each species has its own preferences - one species damages forest plants, another garden, a third garden, and a fourth species of beetle damages the point of growth, as a result of which the plant dies.

Description

Weevils range in length from 1 to 30 mm. The body shape of beetles of this genus can be flat and oblong, cylindrical, rod-shaped, rhombic, spherical, convex hemispherical or pear-shaped. The color varies from yellow to black, the body may have spots, it may have a metallic cast. The legs of an insect may differ in color from the body. The upper part of the body of the weevil can be hairy or bare, it can be covered with an earthy crust or glazed brown scales. A characteristic feature of the insect is the elongated front part of the head - the proboscis, because of which the genus of insects got its name. Longhorns are divided into two subspecies - short-proboscis and long-proboscis, which differ from each other in the length of the proboscis.

Larvae of long-stemmed species usually develop in plant tissues, consuming them as food, while larvae of short-stemmed species live in the soil, feeding on plant roots. Long-horned beetles live mainly on berry crops, and they are attracted not by fruits, but by flower buds, in which the female lays her eggs. The larvae that have emerged from the eggs eat the flower from the inside, and if there are many weevils, you may not wait for berries at all.

Ways of fighting

This dangerous and omnivorous pest has to be fought with all available means - preventive, physical-mechanical, chemical and biological.

As a preventive measure, before receiving and placing the grain, the warehouses should be disinfected against the barn weevil - wet or aerosol, and then the grain should be treated - dried, cleaned of weed impurities, cooled as much as possible and, if necessary, treated with contact insecticides.

In country plots where other types of pests are common, for preventive purposes, loosening of tree trunks, removal of fallen leaves, dry and diseased branches, planting pest-repelling crops in the rows, preventive treatment of plants with insecticides, attracting birds to the site by making birdhouses on trees , and when weevils appear before mating and laying eggs, they are collected by hand or shaken on a dense fabric spread under trees or bushes, after which the pests are destroyed.

Agrotechnical methods of control also include:

• in autumn, clean tree trunks of the old bark that has peeled off, then burn the plant remains, and whiten the trunks with lime solution;
• also remove the fallen leaves from under the trees in the compost pile or burn them;
• during fruit ripening, collect and destroy carrion so that the larvae do not enter the soil;
• immediately after flowering, if you find more than 8 beetles on the tree, treat it with any of the chemicals we have described.

Protection against weevils

Both chemical and biological insecticides are used to combat this pest. In order to reduce the negative impact of chemical insecticides on humans and beneficial entomophages, we recommend using biological insecticides: Imexab™ and Bacitoxin at the rate of 10 ml per 10 liters of water; to increase the effectiveness of the insecticides, add 2 ml of Izomax™ adjuvant per 10 liters of water to the working solution.

It is not recommended to use these products prophylactically. They must be used when pests appear.

The most common types of weevils are:

• Strawberry weevil is a gray-black long-stemmed bug up to 3 mm in size. In the spring, individuals mate in flower buds, which later develop into larvae. Timely response and treatment of plants allow up to 40% of the crop to be saved even with total plant damage.

• Cherry weevil, also known as the cherry elephant, affects not only cherry trees, but also cherry, plum, apricot, plum and even hawthorn. It is a golden-green bug 5.5 to 10 mm long with a purple metallic cast. Larvae are white, dotted with sparse red hairs, with a brown head and brown mouthparts. The cherry weevil causes damage to the generative organs of stone fruit crops even before the sap movement begins - the buds of the trees dry up and fall off. The invasion of this pest can lead not only to crop loss, but also to the death of trees due to damage to the leaves.

• Plum weevil is a bronze-colored bug with a metallic luster up to 45 mm long, completely covered with short thick hairs, and is also called a copper weevil due to its appearance. It affects not only plum, but also blackthorn, apricot, cherry, cherry, and sometimes apple, hawthorn, rowan and even currant. Damage is caused by both adult insects that successively damage buds, buds, flowers, peduncles, young fruits and leaves, and larvae that develop in fruits.

• Raspberry weevil - raspberries are damaged by the same type of weevil as garden strawberries. The main damage to the plant is caused by the female weevil, which can damage up to 30 buds in one season, laying eggs in them, from which larvae emerge after 6-7 days, which eat the flowers from the inside for three weeks. It is possible to prevent the appearance of weevils on raspberries by taking preventive measures of protection, which we have already described to you, but if preventive measures did not give results, start treating raspberries with chemical and then biological means.

• Nut weevil or nut weevil is a brown bug 7-10 mm long. Its females lay eggs in unripe hazelnuts at the end of April, and the larvae, developing, feed on the pulp, as a result of which most of the crop can be lost. Favorable conditions for the appearance of a weevil on a nut are high humidity with an average daily temperature of about 19 ºC. As a preventive measure, digging up the soil in the trunk circle to a depth of 25-30 cm, collecting fallen and wormy nuts and treating with insecticides can be considered.

• Long-nosed large pine beetle - a dark brown beetle 7-14 mm long. Three- to six-year-old pines and Christmas trees are damaged exclusively by adults, eating their bark to sapwood.

The wounds from these injuries merge, becoming covered with resinous juice, which makes the trunk tarry and the tree dies. The pine weevil is also dangerous for those that damage deciduous trees - oak, alder, birch and others, if they are near a pine or fir tree.

Two more types of weevils damage conifers - pine weevil and blue pine weevil. The pine weevil, also known as the pine elephant, is a dangerous pest of conifers that damages the bark of trees, which can cause the plants to die. It is a brown bug with yellow dots forming two longitudinal stripes on the body.

The blue pine weevil is a beetle with a bluish tint that eats holes in young coniferous shoots and lays eggs in them. Larvae of the blue pine weevil eat into the wood, make moves there and pupate. Conifers suffer from both adults of the blue weevil and its larvae. In case of severe damage to plantations, systemic chemical insecticides are used.

As you can see, the family of weevils is very diverse and covers many cultures, so we recommend preventing its development and carrying out preventive agrotechnical measures.