Why are spider mite problems worse during drought?
Spidermites populations are held in balance by natural enemies, weather and host quality. Drought triggers spider mite outbreaks in soybean and corn by upsetting this balance in four ways. • Drought stress accelerates spider mite movement to soybean and corn from surrounding permanent vegetation and alfalfa as it dries down or is cut for hay. Cutting initiates mass movement into adjacent soybean under drought conditions. • Drought stress improves the food quality of soybean for spidermites. • Drought diminishes or stops the activity of naturally occurring fungal diseases that attack mites, such as Neozygites. Disease outbreaks are fostered by cool, highly humid conditions that favor spore formation and mite infection. Hot dry weather stops these diseases in their tracks. • Hot temperatures also speed spidermite reproduction so that predatory insects and mites can’t keep up. How do spider mites injure plants? Spider mites injure leaves by piercing cells and sucking our cell contents. Th
