Genus Curculio - Nut and Acorn Weevils

The word 'curculio' is used in common names of a number of weevils belonging to other taxa, sometimes other families

Curculio Linnaeus 1758

~30 spp. in our area, >350 total(1)(2) [C. rubidus recently found in MI(3)]

body 4.2–13.0 mm(3)

Long slender beak; body robust. In some species, female snout may be longer than the body (never in males).

The female's snout is longer than the males, often longer than her body.(6)

widely dist., except n. Rockies (BG data)

Associated with various Fagaceae, Juglandaceae, and Betulaceae(1)

Female uses her long snout for boring into nuts/acorns, and deposits eggs there. Larvae feed inside the acorn/nut and emerge to pupate in the soil.

Adults usually appear 2-3 weeks before acorns and nuts begin to ripen(7)

The female drills a hole through the nut's shell and excavates one or more chambers near the inner surface, then deposits one egg per chamber. The larvae feed on the nut meat then cut exit holes before entering the soil. They burrow down 1/2 inch to 1 foot where they form cells for pupation.(7)

Depending on the species, they could be in diapause in the pupa stage for 1-2 years.(7)