Sugarbeets XX-13

Lygus Bugs

Gary L. Hein

lygus bug

Lygus bug, Lygus spp., is a term given to a group of insects that are related and have a similar appearance and life cycle. These insects feed primarily on flowers and developing seeds, but they can damage sugarbeet leaves. Economic damage from this insect would be rare.

Identification (life cycle and seasonal history)

Lygus bugs are green to brown in color with black and yellow markings. They are roughly 1/4 inch long and have a triangular patch on the back between the wings. They overwinter as adults in debris in and around fields. They require approximately one month to complete their development so multiple generations will occur each year. Lygus bug adults will readily move from field to field and are most frequently found in alfalfa fields.

Plant Damage and Response

Feeding from the lygus bugs can cause yellow discoloration and distorted growth (puckering) at the leaf tips. Extensive feeding can result in severe damage to the heart leaves and stunting of the plant. Young leaves that are just developing are most susceptible to lygus feeding. When adjacent alfalfa fields are cut, lygus bugs are apt to move into sugarbeet fields to feed.

Management

Lygus bug presence is rarely severe enough to justify an insecticide application. In this region it has been limited to a few isolated plants in the field. North Dakota State University has established a treatment threshold of a third of the plants infested with one or more lygus bugs.

Product List for Cutworms:

Insecticide	Product per Acre	Preharvest Interval, remarks
chlorpyrifos 4E^1 (Lorsban plus generics)	1.0 pt./A	PHI 30 days; REI 24 hrs.
^RRestricted use pesticide ^1Labeled for chemigation.

Categories: Insects, Sugarbeets, Lygus Bugs.

Date: 04/19/2006