Acorn Weevil

Acorn Weevil - A representative of the most numerous family of beetles, in which there are about 50,000 species. In everyday life, the insect is called acorn elephant, oak fruit or oak weevil. All the names reflect the close connection of the beetle with the fruits of oak trees, which are for him a source of food, a place for egg laying and a cozy nest for the development of larvae.

Biological features of acorn weevil

They are inhabited by acorn weevils in the Caucasus, Crimea, Siberia, and in the European part of Russia in forest belts in which oaks grow. The size of a little body of a beetle varies within 5-8 mm. The back of the diamond-shaped brown color with dark spots. The main feature of the beetle is clearly visible on the photo - its long mouthpiece, due to which it got its name.

Acorn Weevil

Interesting!

Acorn weevil - the owner of the longest proboscis. The length of the oral apparatus is almost twice the size of the insect itself and can reach 15 mm. At the end of the proboscis are the teeth that help weevil drill through oak fruit. Such an impressive rostrum gives the insect a lot of inconvenience during movement and it has to hold the proboscis vertically.

Beetles hibernate under fallen leaves in the upper soil layer. With the onset of heat leave their shelters and come to the surface. Until mid-summer, they feed on young foliage, flowers, shoots of oak, maple, linden, birch. Since mid-July, weevils flock to oak trees. Fruit ovaries contain many nutrients and are a convenient egg capsule.

In order to get the contents of the acorn, the weevil puts a lot of physical effort. Drilling one hole takes from 5 to 8 hours. The drilling process is very time consuming, laborious and requires precision movements. Having determined the point of penetration, the bug first pierces it with its fancy mouth apparatus, then describes a semicircle and returns to its original position. The length of the trunk does not allow the weevil to rest against the acorn and it has to drill a hole, standing on its hind legs and holding the rostrum in an upright position.

Interesting!

The slightest mistake leads to the fact that the oak weevil hangs in the air and dies. In the early cold autumn, such a ridiculous death overtakes a huge number of insects. Most of them are females, since they are the ones who do the drilling for the purpose of laying eggs.

How acorn weevils breed

Acorn Weevil

Females differ from males in larger size and proboscis length. After mating, the female lays eggs under the shell of the acorn, pre-drilled a hole in it. The number of eggs in one fruit depends on the yield.In a low-yielding year, there can be up to 20 eggs in one acorn, under favorable conditions, their number does not exceed 8. One female can lay up to 150 embryos.

After 10-15 days, a white larva with a brown head appears from the egg. The shell of an acorn reliably protects it from the external environment, and the cotyledons make it possible to eat well. The period of maturation of the larva from 20 to 30 days. At the end of this period, she independently gnaws a hole in the acorn and leaves it. In winter, young larvae burrow into the soil, where they build peculiar cradles and pupate.

Harm acorn weevils

Acorn weevil in the photo - the sweetest creature. However, these tiny insects with a bright appearance are able to destroy from 50% to 80% of the crop acorns. The larvae cause the greatest harm, the fruits damaged by them fall prematurely. Distinct acorns can be distinguished by their shriveled appearance, the presence of brown spots on the shell and the presence of larvae excrement inside. Weevils can cause similar harm to hazelnuts.