Which environmental factor most promotes growth of grain mites and psocids?

• A. Low humidity
• B. High temperature
• C. High humidity
• D. Bright light

Answer: (C)

High humidity is the key factor promoting the growth of grain mites and psocids. These pests rely on moist conditions to reproduce and survive; water is essential for their life cycles, and damp environments foster mold and fungi that they feed on, providing both habitat and food. When the air is humid, eggs hatch more readily and populations expand faster, because the moisture supports their development and longevity. Temperature can influence how quickly they develop, but without adequate humidity, their growth is still limited. So, the environmental factor that most promotes their growth is high humidity.