Abstract

                                The individual and interactive effects of three external factors viz. insect population source (P), host seeds for rearing (S) and laboratory rearing conditions (C) on oviposition, per cent seed damage and developmental period of the South Indian bruchid, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae) were investigated. Development of C. maculatus populations from Thanjavur and Coimbatore were studied on two important pulse crops of India, mung bean and urd bean. Temperature significantly influenced the oviposition of the insect with the highest number of eggs laid at 30⁰C. Development time was found to be the shortest for the Thanjavur population reared on mung bean at 30⁰C and 70% RH (inside incubator). The results revealed that rather than the interactive effects of the above three factors, their individual effects on C. maculatus are profound and significant. Hence, it can be suggested that C. maculatus is likely to cause greater damage to mung bean seeds at specific range of temperature and relative humidity during storage.

Key words : Pulse beetle, Biological response, Environmental factors, Oviposition