How to Manage Pests

Pests in Gardens and Landscapes

Onion maggot—Delia antigua

Adult maggots are small gray flies that are somewhat smaller than houseflies. When at rest, they keep their wings folded one over the other. Larvae are creamy white, legless maggots about 10 mm long.

Life cycle

Damage

Onion maggots can attack germinating seedlings, feeding on the developing roots and epicotyl. They can continue to feed on the expanding bulb during later stages of growth, creating tunnels and cavities in the bulb and underground stem. Plants may die or become wilted and yellow. Maggots generally do not cause economic damage to garlic; they are primarily pests of onions.

Solutions

Prevention is the best management strategy. Avoid overfertilization with manure; maggots prefer to lay eggs in rich soil. Disc weeds at least 2 weeks before planting. Plant transplants or pregerminated seeds. Cover seedbeds with protective cloth or cover individual plants to prevent adults from laying eggs near plants.

Onion maggot feeding in onion bulb
Onion maggot feeding in onion bulb

Onion maggot feeding in onion seedlingOnion maggot feeding in onion seedling


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/onionmaggot.html revised: January 8, 2014. Contact webmaster.