Curculio elephas
From BugwoodWiki
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Description
Chestnut weevil adults are small (4.5 - 7 mm), brown, snout beetles. Thorax and elytra are marked with yellow scales. The male has a snout shorter than his body. The female snout is longer than her body. Larvae are creamy white, c-shaped grubs, with brown heads, about 5 - 7 mm long.
Life History
Adult weevils emerge from the soil in August and September and cause feeding damage by piercing nuts with their long, slender snout. After feeding, female weevils turn around and deposit several eggs in each nut through the feeding hole. Upon hatching, the larvae or "grubs" consume the nut meat. Kernals of infested nuts are often completely eaten. After feeding inside the nut for about a month, larvae chew their way out of the nut and enter the soil. They remain in the soil as larvae for 1 - 2 years. The complete life cycle requires 2 - 3 years.
Control
Populations of chestnut weevil can be suppressed by good cultural and sanitation practices. In home plantings, nuts should be gathered daily as soon as they fall and stored so that emerging weevil larvae cannot enter the soil to reinfest. If all newly emerged larvae are destroyed for a period of 3 - 4 consecutive years, weevil populations can be reduced to tolerable levels. Three to four applications of insecticide beginning about August 7 - 10, and repeated at 10-day intervals, will provide control of adult chestnut weevils.
