Lethal and sublethal effects of thiacloprid on Schizaphis graminum (Rondani) (Hemiptera: Aphididae) and its predator Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae)

摘要

Lethal effects of thiacloprid were determined on Schizaphis graminum (Rondani) and Hippodamia variegata (Goeze) at 27 +-1 °C, 65 +-10% RH, and 16:8 (L:D) h. The effect of sublethal concentrations (LC_(10) and LC_(30)) was estimated by the International Organization for Biological Integrated Control (IOBC). The LC_(50) values of thiacloprid for H. variegata and S. graminum were 730.3 and 212.7mg a.i.L~(-1), respectively. Both tested sublethal concentrations negatively affected the demography of H. variegata and S. graminum. The LC_(30) treatments had a higher negative effect on demographic parameters of both tested insects compared to the LC_(10) one. Based on the IOBC classification, the LC_(10) and LC_(30) treatments were found to be harmless for H. variegata and slightly harmful for S. graminum. Therefore, thiacloprid can be suggested to be used in cereal fields where S. graminum and its predators are active.