Hairy chinch bugs belong to the order Hemiptera and the suborder Heteroptera. Their life cycle includes three stages: egg, larva and adult.
Eggs: Elongated and oval, 0.84 mm long and 0.25 mm wide. They are white when first laid, and turn yellow and then bright orange with a white band as they age.
Larvae: Resemble adults, but smaller (0.9 to 3 mm) and with a white band across the middle of their backs. The larvae pass through five growth stages before becoming adults. Wing pads appear during the third stage. The larvae also change colour as they develop. The first two stages are red, the third is orange, the fourth orange brown and the final stage black.
Adults: Adults are black with shiny, transparent wings. These are tiny insects (1 to 2 mm wide and 3 to 5 mm long) with antennae composed of 4 segments. The segments nearest the head and legs are purple. The white wings, held flat against the insect's body, form a distinctive pattern with a black dot on the outside margin of both forewings. Above the two dots is a black Y-shaped line with the open end pointing toward the head. Some individuals have shortened (brachypterous) wings, preventing them from flying.
Adult hairy chinch bugs overwinter in sheltered locations like plant litter, beneath bark, under hedges, in bushes, along roadways and in various building structures. The adults emerge from hibernation when air temperatures reach 7°C.
In spring, each female lays over 200 eggs, at a rate of about 20 a day. The egg-laying period lasts at least 3 weeks, reaching its peak in early June. The females lay their eggs on turf grass, in thatch and on the soil in warm, dry spots.
The larvae emerge 3 to 4 weeks later. Most 2nd and 3rd instar larvae are present in July. It is at this stage in their development that treatment is most effective. It takes 3 to 4 weeks for the larvae to reach adulthood.
There is one complete generation per year in Québec.