Lygus Bugs (Tarnished Plant Bugs)

Lygus Bug (Tarnished Plant Bug) Life Stages

Feeding Damage on Green Beans

Feeding Damage on Apples

Reduce Potential Host Plants by Weeding

HOSTS

Beans
Lettuce
Peas
Potato
Tomato
Lettuce

DESCRIPTION

Both the tarnished plant bug (Lygus lineolaris) and western tarnished plant bug are (lygus hesperus) are present in Utah. Adults are brown with yellow, black, and red markings and have a yellow or green triangle on the upper center of the back. Nymphs are usually lighter in color with dark spotting and a more rounded form.

BIOLOGY

Egg | Nymph | Adult

3-4 generations per year.
Overwinter as adults in plant debris.

SYMPTOMS

Adults and nymphs feed on plant cells (not sap) with piercing-sucking mouthparts. Feeding on seeds causes them to shrivel and heavy feeding on flowers may cause bud drop or flower abortion. Symptoms on foliage have not been documented.

SCOUTING

Visually scout plants or use a sweep net in nearby weeds and regularly examine flowers to monitor for adults and nymphs. Monitor weeds surrounding the crop for plant bug activity.

GENERAL MANAGEMENT

Remove preferred hosts (flowering weeds, legumes, alfalfa) from field edges.
Control weeds within the field.

INSECTICIDES

Treatment decisions should be based on sweep net counts. Applications should be delayed until egg hatch is complete but before the nymphs reach the 4th-5th instar. Broad spectrum insecticides will reduce or eliminate pollinators and beneficial insects such as predatory bugs, parasitic wasps and spiders.

Several products are registered for lygus bug control in Utah alfalfa: beta-cyfluthrin, carbaryl, dimethoate, gamma-cyhalothrin, lambda-cyhalothrin, malathion, methidathion, tralomethrin, zeta-cypermethrin.

Click here to reference insecticide options for small-scale use.
Click here to reference insecticide options for commercial use.

Always verify that the product you are using is labeled for aphid control on the intended plant. Pesticide products are available for both home gardeners and commercial growers.

Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.