Effect of Heating on Bean Bruchid, Callosobruchidae Chinensis L., (Coleoptera: Bruchidae) on Chickpea

Abstract

The effect of heat treatment on different developmental stages of bean bruchid, Ccillosobruchus chinensis L., and chickpea seed viability and moisture content were evaluated. An electric solar simulator panel and an obtuse-base-angle box heater glued from inside with aluminium foil were used for heat treatment. The treatments were exposures to heat from 20-90 minutes at ten minutes interval. Heat treatment of C. chinensis infested chickpea for about an hour resulted in complete adult mortality and failure to lay egg. Eggs treated with heat did not survive exposures to heat for 40 minutes. Similarly, the eggs laid by adults that survived
exposure to heat for 50 minutes failed to hatch. Moreover, larval instars and pupae did not tolerate heating for over 50 minutes. In general exposure of the various developmental stages to heat for about an hour in the aforementioned box heater raised the temperature within and between seeds to 60°C and more that provided effective control o f the pest. Treatment o f chickpea seeds with heat for up to 90 minutes had no adverse effect on seed moisture content and viability. Hence, chickpea seeds meant either for planting or consumption purpose could be protected from the pest by heat treatment