Both BGM and TSM overwinter as orange-yellow females. Some eggs may be laid during prolonged warm spells. Immatures stop moving prior to molting. Generation times depend on temperature and are typically 10 to 20 days. Under laboratory conditions, BGM populations can increase 70-fold in one generation.
Banks grass mite overwinters on alternate grass hosts.
Mites return to corn either by walking short distances or by being windborne on silk threads over longer distances. Infestations start on the undersides of lower leaves and gradually move into the upper part of the plant. Banks grass mite is commonly found in corn from the mid-whorl through the grain filling growth stages, while TSM is rare on corn before flowering. Rapid population growth most commonly occurs after pollen shed. Factors that encourage BGM infestations include host drought stress, elevated temperatures, low rainfall, low humidity, absence of TSM, lack of natural enemies, insecticide use, and adequate moisture for alternate hosts during the previous growing season.