These small, grayish insects develop on a wide variety of plants, but start the season on winter annual mustards. They can cause damage to a wide variety of crops, but actually seem to do relatively little injury compared to the very large numbers in which they typically appear. Nuisance problems, as they invade homes and business, have probably been more important. False chinch bugs suck the sap from plants during feeding. The adults may appear in tremendous numbers, causing plants to wilt and die rapidly.
Outbreaks are sporadic but can destroy plantings, particularly early in the year.
Most garden plants can be damaged during outbreaks, but beets or cruciferous plants such as radish and cabbage are favored. Wild hosts include many weeds such as tansy mustard, kochia, Russian thistle and sagebrush. This insect is sometimes a nuisance pest of homes and buildings in summer when they migrate indoors. False chinch bugs spend the winter as nymphs or adults under protective debris near winter annual mustards that they use for hosts. Some adults also will move to buildings or other sites outside plantings to survive winter.