Habitat and Life Cycle Several species of spider mites occur in Nevada. The two-spotted spider mite is the most widespread. It occurs on a wide variety of indoor and outdoor plants. Spruce spider mites are found on junipers, spruce and other needle-leafed evergreens. Clover mites occur as periodic pests of lawns and are a nuisance when they migrate into homes.
Most spider mites overwinter as adults, hidden in bark cracks or under debris around gardens.
As air temperatures warm in the spring, mites become active and begin to feed and mate. Adult females may lay dozens of eggs over a two week period. This takes a few days to several weeks depending on environmental conditions, the availability of food, and pressure from natural enemies. Environmental conditions have an important influence on the development of spider mite populations. Populations grow rapidly when weather is hot and humidity is low, and when plants are water-stressed from drought or improper irrigation.