Plants

Acorn weevil

 

The acorn-fed weevil (Curculio elephas) is a beetle of the Curculio genus of the Curculionidae family, living mainly in southern Europe. The larvae live inside the fruits of the trees of the genus Quercus (oak, holm oak, cork oak …) and chestnut trees.

Description of the weevil of the acorns

The adult acorn weevil measures six to nine millimeters without counting its front beak. The most characteristic feature is the length of the female’s buccal apparatus in the form of a “trunk”, which inspired her scientific name elephas or elephant. It serves first to drill a gallery in the acorn and then to introduce the egg. The male has more modest dimensions.

The larva feeds for forty days, and when the mature acorn has fallen the larva comes out and digs a gallery 10 to 60 centimeters deep, where it winters. The pupa of most is made towards the end of the following summer, between 25% and 40% of the larvae have a dormancy period of two to four years. Adults come out towards the end of summer, after mating, the female lays up to forty eggs. There is one generation per year.

Control of the weevil of the acorns

Fruit growing is the sector where the economic damage is greatest. Chestnuts grown for human consumption can be damaged, especially since infected and unpeeled fruits can hardly be distinguished from the good ones. Holes and feces make them inedible.

Generally, chopped acorns fall before healthy ones. In cork oaks, up to 90% of acorns can be contaminated.

In their hiding place inside the fruit, they are protected against any insecticide. The only phase where they are vulnerable is when the larvae have come out of the acorn or chestnut and have dug their greenhouse in the ground. If the trees are in good health, the attack becomes more difficult.

The only control that can be done is to quickly collect the fallen chestnuts or acorns, before the larva has come out, choose them and burn the contaminated fruits.

 

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Robert Asprin, APD is a non-dieting Accredited Practicing Dietitian passionate about inspiring positive changes in eating and lifestyle behaviors to help improve health while nurturing relationships with food and body.

Robert Asprin

Robert Asprin, APD is a non-dieting Accredited Practicing Dietitian passionate about inspiring positive changes in eating and lifestyle behaviors to help improve health while nurturing relationships with food and body.

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