Description:Body - Pale green turning darker to blue black as it feeds with a red spot (anus) on its back. 1 mm long.
Biology:Blue Oat Mite is polyphagous but tend to feed primarily on pasture grasses, cereals and peas.
Life Cycle:Active during cool, moist period of year, autumn to spring, and produces drought resistant over summering eggs in spring which remain dormant until following autumn. The over summering eggs are laid on the underside of leaves or on the soil surface around the host. Dormancy of the eggs is broken with the combination of low temperatures (less than 200C) and moisture. They pass through 3-4 stages after hatching before becoming adults (egg to larva, protonymph, deutonymph to adult). Generally 2 to 3 generations occur annually depending on length of growing season. Activity ceases with laying of over summering eggs with the onset of warmer temperatures and the drying of the soil.
Habitats:Origin and History:
Distribution:They are a major pest in NSW.
Significance:The Blue Oat mite is mainly a pest of pastures in southern Australia. It also is known to cause damage to a wide range of vegetables, lemons, peanuts, cotton, grasses and small grains. It feeds on the upper surface of leaves using its sharp chelicerae to pierce the surface and consume the plant sap as it is exuded. The leaf tips turn brown and appear scorched. Plants may become stunted, producing little forage or grain and take on a silvery appearance. In pastures the Blue Oat Mite prefers grasses unlike the Redlegged Earth Mite which generally feeds on leguminous species.
Management and Control:Six organophosphate insecticides are registered for the control of the blue oat mite; chlorpyrifos, methidathion, azinphos-ethyl, dimethoate, omethoate and phosmet
Related Species:Redlegged Earth Mite (Halotydeus destructor) has a dark or black body with red legs.