Filbertworm: Appearance, Territory, Damage and Life Cycle

Latin Name: Cydia Latiferreana

Appearance: Filbertworm is a near relative of codling moth, one of the most economically significant insects in the world, and is a major pest of hazelnuts in the Pacific Northwest. Adult moths’ range in color from gray to reddish, with golden stripes across each forewing. Female moths lay their eggs near nut clusters, and the larvae must find the nuts to gain admission. Larvae feed inside the nut, destroying the kernel. The larvae are pale with a brown head-capsule and about 0.5 inch long when completely mature.

Filbertworm is a natural bug found across California that is a sporadic pomegranate pest. In late spring to early summer, the little bronze, copper, or reddish-brown moths emerge. The eggs are scale-like, flattened oval in form, and resemble codling moth eggs.

Hosts Plants: Filbertworm’s major host is oak trees. During the summer and fall, adult females gnaw a tiny hole in the seed coat of acorns or other nuts on the tree and insert one or more eggs. Hatching larvae penetrate into the nutmeat. During the summer, heavily damaged nuts may fall early.

Territory: Filbertworm is a natural bug found across California that is a sporadic pomegranate pest. In late spring to early summer, the little bronze, copper, or reddish-brown moths emerge.

Damage Insect Cause: Filbertworm can wreak havoc on pomegranates. Infestations have been observed in just a few orchards, the majority of which are located near other hosts such as oak. In July, the larvae bore into the fruit in the same way as a close relative, the codling moth, does. Damage at the entrance of the larval tunnels is common in codling moths.

Life History and Habits: The insect may be found in a variety of wild and cultivated nuts in North America, although it is most common in acorns and hazelnuts. The filbert worm spends the winter as a larva in a silken cocoon beneath leaves and rubbish on the ground or in tree cracks and crevices. Some larvae may hibernate 1 to 2 inches under the soil’s surface during the winter. In the spring, the larvae pupate, and the adults emerge from mid-June to October. After mating, female moths begin to lay single eggs near developing nuts. In 8 to 10 days, the eggs hatch, and the little larvae search for nuts. Before emerging as fully fledged larvae, they burrow into the nut for 2 to 4 weeks to feed on the kernel. Most pupate and become moths during that season, although some may create cocoons to overwinter.