Spider mite destroyer (black lady beetle)
General Description
Spider mite destroyers are small black lady beetles that feed mainly on mites. They are usually found in orchards with high spider mite or rust mite populations and can help reduce mite numbers.
Hosts
All stages of plant-feeding mites
Damage
Identification
Egg – oval, about 0.4 mm long, pale yellow to white when laid, gray to black before hatching. Eggs are laid singly in mite colonies.
Larva – oblong, 1-1.5 mm, dark brown or black, covered with small hairs.
Pupa – oval, black, brown, gray, or reddish depending on maturity, covered with tiny pale hairs, usually attached to a leaf surface.
Spider mite destroyer pupa. Photo Credit: Matt Walz, BC Tree Fruits Cooperative.
Adult – black, dome-shaped, 1 mm long, covered with small silvery hairs.
Spider mite destroyer adult (top) and larva (bottom). Photo credit: Washington State University
Life History
Adult females lay eggs singly in spider mite colonies. Females lay about 100 to 200 eggs during their lifespan. There are four larval stages. The spider mite destroyer can complete development from egg to adult in 3 to 4 weeks during warm temperatures. There are 3 – 4 generations per year.
Monitoring
Inspect mite colonies for adults, larvae and pupae or use a beating board. Adults are easy to see with the naked eye and are frequently tapped out onto beating boards when monitoring for mullein bugs and other beneficial insects.