CRITICAL TEMPERATURE CHANGE AS IMPORTANT FACTOR OF CALLOSOBRUCHUS CHINENSIS L. MANAGEMENT IN CHICKPEA GRAINS

Pulse beetle, Callosobruchus chinensis L., is a major pest of stored chickpea. To reduce infestation of chickpea grains by this pest, the impact of short temperature changes on various life cycle aspects of this pest on chickpea grains was studied. Shifts of temperatures, from the average storage temperature of 30 o C, of plus or minus 5, 10 or 15 o C for either five or ten minutes each day for two days, was sufficient to affect the life cycle of the pest and reduce infestation. In general the larger the temperature shift and the longer the time at the shifted temperature, the greater was the effect. The treatment of 15 o C for 10 minutes proved to be the most effective reducing the number of days to death from 19.77 to 4.97 days, the number of eggs laid per grain from 3.92 to 1.21 eggs, the number of F1 adults per test sample from 13.71 to 0.93 adults, the lifespan of F1 adults from 18.39 to 2.75 days, the number of holes per grain from 1.63 to 0.18 holes and the percent weight loss of grains from 29.61 to 8.69%. These data suggest that short, but significant, changes in temperature can adversely affect the physiology of this pest and provides a potential method for reducing product loss.