Abstract
Stored cereals and food products are severely infested by different insect pests throughout the world but Trogoderma granarium is found most destructive insect pest of stored grains. Temperature and relative humidity affects the growth and development of these insect pests of stored grains. Present study was designed to investigate the effects of temperature (20, 25 and 30 degrees C) and relative humidity levels (55, 65 and 75%) on the efficacy of three synthetic Insect Growth Regulators (IGRs) i.e., pyriproxyfen, lufenuron and buprofezin at concentrations of 1, 5 and 10 ppm. The study aimed to estimate the fecundity and adult emergence inhibition of T. granarium under controlled laboratory conditions. Counted numbers of grubs were exposed to IGRs at different levels of temperature and relative humidity. F-1 adult emergence results at 20 degrees C; showed highest percent reduction in adult emergence (84.38, 70.65 and 79.94%) when exposed to lufenuron, buprofezin and pyriproxyfen treated diet, respectively. At 75% relative humidity lufenuron, buprofezin and pyriproxyfen caused 77.53, 80.00 and 80.32% reduction in adult emergence, respectively. Adults were exposed to IGRs at different temperature and relative humidity to evaluate the oviposition inhibition too. Percentage of reduction in fecundity (87.95, 80.45 and 70.55%) perceived after exposure to buprofezin, pyriproxyfen and lufenuron treated diet, respectively at 20 degrees C was found highest. While 75% relative humidity reduced fecundity most effectively (86.73, 83.72 and 69.11%) when test insects were treated with buprofezin, pyriproxyfen and lufenuron, respectively. It is concluded that temperature and relative humidity significantly affected the activity of tested growth regulators which may lead to standardization of abiotic factors to gain maximum efficiency of IGRs in future.