Factors favoring spider mite outbreaks

Hot, dry, dusty conditions favor spider mites.

Mite infestations are favored by hot, dry weather (5).  Very high relative humidities and rain tend to harm spider mites by killing them during molting, washing them off leaves, and favoring pathogenic fungi that can cause rapid declines in mite populations.  Mite infestations are favored by application of broad spectrum pesticides.  Pesticides reduce populations of predators that keep mite populations in check.  Dusty conditions from dirt roads, drought conditions, vehicle movements, and wind also favor mites, possibly by interfering with predator searching efficiency.