Sublethal Effects of Emamectin Benzoate on Food Utilizationof Bombyx mori Larvae

Effects of mulberry leaves treated with emamectin benzoate at sublethal doses of LC5、LC10 and LC20 on food utilization of 3rd and 4th instar larvae of silkworm (Bombyx mori) were studied by gravimetric method.The results indicated that the tested chemical had obviously inhibiting activity on the growth and food utilization of the 3rd and 4th instar larvae at sublethal doses of LC5,LC10 and LC20.The growth indices such as the increase of body weight and relative growth rate (RGR),nutritional indices such as relative consumption rate (RCR), feces weight, nutritional efficiency parameters such as efficiency of ingested food (ECI) and efficiency of conversion of digested food (ECD) of the 3rd and 4th instar larvae were decreased greatly after the larvae were fed with leaves treated by sublethal doses of emamectin benzoate,however the approximate digestibility(AD) was increased significantly.The RGR,RCR,ECI and ECD of the 3rd and 4th instar larvae were reduced by 19.6% ~66.1%,13.9% ~23.6%,6.6% ~57.0% and 9.3% ~66.2%,respectively 2 d after treatment.