Effect of temperature and relative humidity on consumption and digestion of food (bark) by the larvae of Indarbela quadrinotata Wlk. (Lepidoptera: Indarbelidae)

The influence of temperature and relative humidity on consumption and digestion coefficient of food in Indarbela quadrinotata Wlk., a polyphagous bark feeding caterpillar, was investigated. The food consumption increased with corresponding increase in temperature(35°C), the maximum being 166.0mg/day and minimum 16.0mg/day at 12.5°C. The digestion coetficicnt followed a reverse trend, the maximum being (60.5%) at 15°C and minimum 19.0% at 35°C. The food consumption was maximum (97.0 mg/day) at 96% R.H. which decreased with lowering the R.H., the minimum being 3.0 mg/day at 56% R.H. The digestion coefficient also followed the same decreasing trend. Consumption and digestion pattern with the advancement in larval age (weight) revealed adefinite range of temperature and relative humidity needed for normal physiological function.