How to Manage Pests

UC Pest Management Guidelines

Sugarbeet

Leafminers

Scientific name: Liriomyza spp.

(Reviewed 11/05, updated 11/05)

In this Guideline:


DESCRIPTION OF THE PESTS

Leafminer adults are small flies with yellow and black markings. Females lay eggs on the surface of the leaves. When eggs hatch the larvae burrow into the leaves and feed on plant tissue. The larvae are small, legless maggots that are frequently found next to main veins.

DAMAGE

Both larvae and adults cause damage to plants. Larval feeding results in slender, winding trails on the leaves, which form large, white blotches when mining becomes severe. Adults damage plants by carving small pits on the leaf surface with their ovipositors and feeding on plant exudates. There may be as many as 100 feeding punctures on a single leaf. Around 5% of these punctures may contain actively feeding larvae.

MANAGEMENT

The larvae and adults are most active in spring, with several generations that follow in quick succession. Natural enemies can provide good control of the pea leafminers, and 50 to 90% parasitism of the larvae is not unusual. Several species of parasitic wasps from the genera Diglyphus, Opius, and Dacnusa attack leafminer larvae. Some of these species are commercially available.

No economic thresholds have been established, though plants appear to outgrow feeding damage by larvae and adults, and treatment is not usually required.

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Sugarbeet
UC ANR Publication 3469

Insects and Mites

E.T. Natwick, UC Cooperative Extension Imperial County
Acknowledgement for contributions to Insects and Mites:
C. G. Summers, Entomology, Kearney Agricultural Center, Parlier
D. R. Haviland, UC IPM Program, Kern County
L. D. Godfrey, Entomology, UC Davis

Top of page


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/r735301611.html revised: April 25, 2014. Contact webmaster.