Curculio elephas

Curculio elephas is a species of beetle in the family Curculionidae, the true weevils. It is known commonly as the chestnut weevil. It is a serious pest of chestnut (Castanea sativa).[1]

The adult female weevil drills a hole in a chestnut fruit and deposits one egg inside. When the larva emerges it feeds on the fruit. It emerges from the chestnut, drops to the ground, and immediately buries itself several centimeters deep in the soil. Larvae may pupate in the soil for one season or for several years. The adult emerges and lives in the canopy of the chestnut tree.[1]

In some chestnut-growing regions, infestation of the fruit by weevil larvae can reach 90%.[1]

Chemical control of the pest is difficult. Other suggested control methods include collecting fallen chestnuts which may contain larvae, and the use of biological pest control agents, such as fungi.[2]

This insect is not limited to the chestnut. It is also a main predator of the seeds of holm oak (Quercus ilex). The larvae feed and develop inside the acorns.[3]