Many generations occur each year. Under optimal conditions, populations can build up very rapidly. Spider mites on conifers and broadleaved evergreens are cool weather pests. They feed heavily and reproduce quickly in spring and fall. Activity is low during the hot part of summer, although damage is often at a maximum and becomes easier to see when other plants are green and growing normally.
Spider mites on honeylocust, linden, elm, willow, and oak are destructive in the summer.
The two-spotted mite thrives whenever conditions are favorable for plant growth. European red mite and two-spotted spider mite. Damage Spider mites lack chewing or piercing-sucking mouthparts. Instead they have a pair of needle-like structures called stylets which are used to rupture leaf cells. A feeding spider mite pushes its mouth into the torn tissue and draws up cell sap.