Toxicity of insecticides to predators of rice brown planthopper: Wolf spider and carabid beetle

Abstract

Field toxicity two insect growth regulators (IGR) viz. Award 40 SC (Buprofezin) and Haron 5 EC (Lufenuron) and one newer Thiacloprid viz. Calypso 280 SC against wolf spider, Lycosa pseudoannulata and carabid beetle, Ophionea indica, the predators of rice brown planthopper (BPH) was examined in the Entomology field laboratory, Bangladesh Agricultural University, Mymensingh. Effectiveness of insecticides was assessed on the basis of populations of wolf spider and carabid beetle under field condition at 1, 2, 3, 5 & 7 days after treatment. The abundances of wolf spider and carabid beetle were not changed significantly even when rice plants were treated with either Award or Haron. In contrast, Calypso 280 SC had significantly reduced wolf spiders (about 78%) and carabid beetle (about 57%) populations compared to the control. Therefore it is concluded from the present study that Award 40 SC @ 0.75 ml/L or Haron 5 EC @ 1.00 ml/L would be applied as the protector of predators of BPH in rice-ecosystem. On the other hand, Calypso 280 SC has adverse effects on the populations of wolf spider and carabid beetle in rice-ecosystem as well as other environmental components.