Fully grown chinch bugs are ~ 3/16" long, with black body and white forewings. Newly hatched bugs are very small and bright red. There are five nymphal instars.

Damage Symptoms:

Injures plants by sucking plant juices, causing stress on the plant. Feeding can occur at crowns and below soil surface on roots and stems of small plants; later, bugs may feed on stems behind leaf sheaths.

Incidence:

Throughout the growing season, primarily southeastern and south central Nebraska. Populations build up during dry years.

Sampling Scheme:

Inspect border rows of cornfields planted near ripening small grains for chinch bug migration. Examine 25 plants in at least 4 locations in field for reddish nymphs or black and white adults feeding on leaves or stems below the soil surface. In June, examine plants near ripening small grains. In August, may be anywhere in the field.

Economic Threshold:

10 or more on 3" plants. 50 or more on 12" plants. Economic threshold lower if plants are under stress.

More Information and Treatment Recommendations:

http://www.unl.edu/entomology/extension/crops/fieldcorn.shtml