Abstract

The development and viability of the leaf cutting weevil, Eugnamptus marginellus Fst. was evaluated under laboratory condition at seven different constant temperatures, viz., 14±1°C, 15 1°C, 20±1°C, 25±1°C, 30±1°C, 35±1°C and 36 ± 1°C. Freshly laid eggs were allowed to incubate separately at seven temperature regimes and allowed to develop till adult emergence. There was decrease in egg perind with increase of temperature from 15 ± 1°C - 35±1°C and with the increase of temperature from 15±1°C-35 ± 1°C there was increase in hatching percentage but the rate of hatching was lowered at 35 ± 1°C. None of the eggs hatched at lower temperature below 15+ I°C and upper temperatures above 35 ± 1°C indicating threshold level for egg development. The larval, prepupal and pupal period were found to decrease with the increase of temperature from 15± 1°C-30±1°C and 25±1°C-30±1°C but none of the prepupal larvae transformed into pupae when exposed to 151°C-20±1°C.

Keywords: Leaf cutting weevil, Eugnamptus marginellus, constant temperature, development