In what conditions do two-spotted spider mite populations increase rapidly?

Two-spotted spider mites thrive under conditions of severe drought, which allows them to reproduce rapidly. These mites are adapted to dry environments and often experience less competition and fewer natural enemies when moisture levels are low. Consequently, the stressful conditions for many plants can lead to a more favorable environment for spider mites, resulting in population explosions.

In contrast, wet and humid conditions tend to support the growth of fungal pathogens and introduce moisture that can be unfavorable to spider mites. Cool temperatures can slow down their life cycle, limiting their reproductive potential. Heavy rainfall can wash away mites and introduce predation or competition from beneficial insects, further reducing their population growth. Thus, severe drought is indeed the best scenario for the rapid increase in two-spotted spider mite populations due to these combined factors.