Agriculture Information

Cereal Leaf Beetle

The cereal leaf beetle (CLB) was first detected in Washington State in 1999. As of 2002, CLB has been found in fourteen counties including Ferry, Stevens, and Pend Oreille.

The insect causes significant damage by feeding of the leaves of small grains and grasses, including barley, oats, wheat, bluegrass, timothy, rye, orchardgrass, and corn. Typically both adults and larvae feed lengthwise, between the veins on leaves, and can cause the plant to have a tattered and/or whitened appearance.

During late June and early July the larvae are the most visible stage of the insect in the field. An average of one larva per flag leaf will cause a five- to six-bushel loss of grain per acre. Adults chew completely through the leaves, creating narrow slits between the veins. Infested fields have a frosted, withered appearance. CLB move from winter cereals to spring cereals as the season progresses.

The adult CLB is about 3/16 inch long with a metallic bluish-black head and wing covers and a dark red thorax. The females lay their eggs (1/16 inch long) on leaves. They are yellowish initially but darken before hatching. The CLB larva, which is slightly longer than the adult, has a brownish-black head and legs with a yellowish body, but it appears dark as it is usually covered with fecal matter.

The larvae pupate for 10 to 20 days in earthen cells in the ground. New adults then emerge and feed on available lush grasses such as wild oats, timothy, quackgrass, and young corn. Adult beetles are inactive during the hot periods of summer. They overwinter in stems of grain stubble, behind corn sheaths, under field trash, or in crevices in the ground.

It is important that growers monitor the larval stages and eggs for economic thresholds prior to making management decisions. The best strategy is to sample 10 plants every 10 acres, looking for eggs and larvae on all plant parts during all crop stages. The current economic threshold is 3 eggs and/or larvae per plant up to the boot stage in spring cereals. At the boot state the economic threshold drops to 1 egg or larva per plant.

Biocontrols have been every effective in managing CLB populations in most areas of the US, and the WSDA has released parasitoid species at Nine Mile Falls. There are several chemicals labeled for controlling CLB, but establishing biocontrols is the preferred management. Some preliminary data from Utah indicates that CLB populations can increase in fields following an insecticide treatment.

This information was taken from a report prepared by Diana Roberts, WSU Cooperative Extension Agronomist in Spokane. She can be reached at 509-477-2167 or robertsd@wsu.edu.

Photos and introductory information was taken from the WSDA web site for CLB.

Agriculture and Natural Resources

The Stevens County office is committed to developing a community-based food system that gives local citizens an option to buy local products and gives local farmers an opportunity to make a reasonable profit. The range of products we have in mind goes from fruits, vegetables, and herbs through poultry and livestock products. We are currently working on two projects that help to create this system: a community kitchen and a mobile poultry processing unit. We encourage sustainable production systems that enhances biological activity in the soil. We offer an extensive courses in developing or improving an agricultural enterprise including production, marketing and financial management.