Tip Top Bio-Control Technical Bulletin

Amblyseius degenerans
Predatory Mite

Target Pests:
Western flower thrips (Frankliniella occidentalis). Onion thrips (Thrips tabaci). Various thrips species; first larval stage.

Description:
A. degenerans is a species of predatory mite that feeds on immature stages of thrips. It also feeds on pollen, and other species of mites and does not like leaves having webs. Cucumeris adults are pear-shaped; dark brown colored mites, less than 0.5mm (1/50 inch) long.

Product information:
About 50% are female. Well-fed females will lie up to 3 eggs per day producing about 25 eggs. The eggs are round, initially transparent, later turning brown and 0.14mm (0.01 inch) in diameter and usually deposited on hairs on the underside of leaves. A. degenerans are delivered in a bottle or vial with adults and nymphs and shipped in a vermiculite carrier.
The contents are gently sprinkled onto leaves. Upon receipt active predators should be visible at the top of the containers.

Release Rates:
Relatively high introduction rates are required because thrips can reproduce nearly twice as fast as A. degenerans and only feeds on immature thrips, not adults. Rate will vary depending on crop and level of pest infestation. Typical rate is 5 predator per square foot. One bottle/vial should be introduced in many different spots.

Lifespan of A. degenerans:
A complete life cycle takes 7 days at 68° F. Adults live for up to 30 days.

Strategic Considerations:
A. degenerans are found more in flowers than A. cucumeris. The eggs of A. degenerans are less susceptible to a low relative humidity. The eggs will still hatch at an RH of 50%, Whereas cucumeris require at least 65%

Pesticides and even wetting agents and spreader-stickers may adversely affect A. degenerans survival. Broad spectrum and systemic insecticides are toxic to A. degenerans.