How to Manage Pests

Pests in Gardens and Landscapes

Filbertworm—Cydia latiferreana, Filbert weevil—Curculio occidentis,Acorn moth—Valentinia glandulella

Acorn moths and filbertworms are larvae of small moths, which are commonly bronze, coppery, or reddish brown. Larvae are light brown, to whitish with a darker head and have three pairs of true legs. Filbert weevils are brown beetles with a long thin snout. Larvae are light brownish, yellow, or white. Filbert weevil larvae have no obvious legs, are relatively inactive, and may curl into a C shape if disturbed.

Identification of species


Larvae of filbertworms, filbert weevils, and acorn moths commonly infest oak acorns and may also damage other nuts, including almond and chestnut. Moth and weevil larvae make holes in acorns or nuts, bore inside and feed, destroying kernels. Tunnels inside acorns may contain whitish larvae. Insect-damaged acorns may become colonized by bacteria, causing drippy oak.


No methods have been demonstrated to control these weevils and moths. Acorns on the shady side of trees are more likely to be attacked than those on the sunny side. The pests may reduce natural oak regeneration, but established trees are not damaged. If collecting acorns, inspect and discard damaged nuts before storing or planting them.

Adult filbert weevil
Adult filbert weevil

Damage to acorns
Damage to acorns

Statewide IPM Program, Agriculture and Natural Resources, University of California
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