What environmental factor has the greatest effect on insect growth rates?

Temperature plays a crucial role in determining the growth rates of insects. Most insects are ectothermic, meaning their body temperature and metabolic processes are influenced by the ambient temperature of their environment. As temperature rises, so does the rate of physiological processes such as digestion, reproduction, and development.

In warmer conditions, insects generally experience shorter development times and increased rates of reproduction, as long as other factors, such as food availability and moisture, are also favorable. Conversely, low temperatures can slow down these processes, leading to delayed growth and development.

While moisture, photoperiod, and soil type can certainly impact insect life cycles and behaviors, temperature has a more direct and immediate influence on metabolic rates across a wide range of species. This makes it the most significant environmental factor affecting growth rates in insects.