European red mites belong to the class Arachnida, like spiders, and the order Acari, along with other mites and ticks. They pass through the egg, larva and nymph stage before reaching adulthood.
Eggs: Spherical, about 0.13 mm in diameter; dark orange to bright red, with a tassel or stalk.
Larvae and nymphs: Resemble adults but smaller; nymphs have eight legs and larvae six.
Adults: Oval, brick-red body. The back is marked with four rows of white dots with long curving hairs. They have four pairs of legs but no wings or antennae. Females grow to about 0.3 mm and males are slightly smaller.
The adults, nymphs and larvae do not survive in winter. Only the eggs overwinter, hidden between the scales on buds, in cracks in bark or on leaves and fruit lying on the ground.
In spring, when the buds begin to swell, the eggs hatch and the young larvae move to the new leaves to feed. They mature in five to twenty days. After mating, the first-generation females lay their eggs on the underside of leaves. They live for about twenty days and each lay about twenty eggs. The rate at which subsequent generations appear depends on the weather, with warmer temperatures shortening the life cycle.
Populations normally reach their maximum in late July and early August. There may be as many as six to eight generations a year.
Starting in late summer (mid-August to October), the females of the latest generations deposit their eggs between the scales on fruit buds, in cracks in bark, on leaves and in the calyx of fruit.