False chinch bugs are not a common pest in Iowa. Outbreaks have been noticed only 3 times in the last 20 years. When outbreaks do occur, large numbers or "swarms" of these tiny insects are observed in yards, fields, fencerows and gardens. Outbreaks are associated with dry weather.
FCB nymphs are quite small, 2-3 mm long, and pointed-oval in shape. They appear orangish or reddish brown, especially on the abdomen. Toward the sides and front of the abdomen are the wing pads that have black tips. The shiny thoraxic segments are mottled tan and black on top, but with a noticeable white line down the middle of the segments. The head is black with reddish-brown, beady eyes bulging to the sides. The head comes to a point in front of the eyes, and the slender beak extends backward from the point along the insect's underside. The four-segmented antennae are prominent.
The adults are similar in shape and head characteristics and are 3.5 mm long. The front half of the adult appears plain black. The wings are white to clear and extend slightly beyond the end of the abdomen. Two or three tiny black spots are present on each wing on a diagonal line 2/3rds of the way back.
Life Cycle and Damage
False chinch bug is a "general feeder" that feeds on sap from a variety of host plants, including vegetables, weeds and other plants. Samples sent to ISU have been from soybean, alfalfa, set aside acres, fencerows, gardens and lawns. Sap feeding damage by this pest generally appears as wilting and death of the plant leaves. Symptoms may vary greatly among host plants.
This insect has 4 or 5 generations per summer. Eggs are laid on foliage or soil and hatch in 4 days. Nymphs feed and grow for about 3 weeks before transforming to adults. Populations build in spring and early summer among "weeds and other uncultivated plants." The bugs migrate into crops when the original host plants become less succulent. Winter is spent in both the adult and nymph stages.
Thresholds for this insect are not known, but in drought-stressed fields and vegetable crops, presence of large populations and apparent damage might warrant treatment. Insecticide selection would vary with the crop or treatment site, but in general the same insecticides used for grasshoppers should provide control.
This article originally appeared in the July 20, 2001 issue, p. 92.