Effect of temperature on biology of Callosobruchus maculatus (F.)

Callosobruchus maculatus (F.) was reared on four varieties (Bio L 212 Ratan, Nirmal B-1, WBK-14-7 and WBK-13-1) of khesari seeds at four constant temperatures (20, 25, 30 and 35°C) and a relative humidity of 70 ± 5% with a photoperiod of 14L: 10D. C. maculatus could not complete development at 20°C. The developmental time from egg hatching to adult emergence of C. maculatus except WBK-147 seed was shortest at 30°C and longest at 25°C; whereas WBK-14-7 fed insects had a faster developmental time at 30 and 35°C. Further, developmental time of C. maculatus was fastest on Bio L 212 Ratan at 30°C, suggesting that greater damage would be due to repetition of several generations annually. Longevity of males and females was found to be shortest at 35°C and longest at 20°C. Fecundity was maximum at 30°C over an incubation period of 6.27 - 7.08 days; whereas this was minimum at 20°C, but failed to hatch.