How to Manage Pests

Pests in Gardens and Landscapes

Tomato pinworm—Keiferia lycopersicella

Tomato pinworm caterpillars are tiny and have a mottled pattern. The color varies from gray to yellowish with red or purple coloring around each segment. Caterpillars may sometimes be quite dark.

Identification of species | Life cycle


Pinworms cause leaf mines and folded shelters on leaves. They bore into fruit at the stem ends, creating narrow, blackened tunnels. Damage is hard to detect at first, but after larvae have been feeding for some time, a brown, granular frass usually appears at the edge of the calyx.


Tomato pinworms are difficult to control with insecticides, and natural enemies are not effective. Disc all plants immediately after harvest. A host-free period of 3 months or more is essential to control pinworms.

Pinworm larva
Pinworm larva

Pinworm folds in leaf
Pinworm folds in leaf

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2014 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/GARDEN/VEGES/PESTS/tompinworm.html revised: April 25, 2014. Contact webmaster.