Minute Pirate Bug

Naming

Orius tristicolor (White 1879)

Distribution

Transcontinental (AK-NS to S America & W Indies); in our area much more common in the west and is absent in se US.

Habitat

Orius is common on many agricultural crops including cotton, peanuts, alfalfa, corn, pea, and strawberry, on pasture land, in orchards, and is successfully used as a biological control agent in greenhouses.

Reproduction

Females lay tiny eggs 2-3 days after mating within plant tissues where they are not easily seen. These hatch into nymphs which develop through five nymphal stages. Egg incubation is generally 3-5 days, and development from egg to adult takes a minimum of 20 days under optimum conditions. Females lay an average of 129 eggs during their life spans, and adults live about 35 days. Several generations may occur during a growing season.

Food

Both immature stages (nymphs) and adults feed on a variety of small prey including thrips, spider mites, insect eggs, aphids, and small caterpillars. Orius holds its prey with its front legs and inserts its beak into the host body, generally several times, until the soft body is empty and only the exoskeleton remains. It has been reported to be an important predator of the eggs and new larvae of the bollworm and of spotted tobacco aphid, but it is believed that thrips and mites are the more basic part of an Orius diet. It can also be an important predator of corn earworm eggs which are laid on the silks. Other reported prey include eggs and small European corn borers, corn leaf aphids, potato aphids, and potato leafhopper nymphs. It is often found in corn silks and is most common where there are spring and summer flowering shrubs and weeds since it feeds on pollen and plant juices when prey are not available

Defense

Orius spp. are "true" bugs and occasionally may bite humans, but the bite is only temporarily irritating.

Uses

In greenhouses, Orius spp. are used as generalist predators, especially on cucumber and bellpepper crops.