Abstract

Acute toxicity of chloronicotinyls viz., imidacloprid, thiamethoxam, acetamiprid and thiacloprid using leaf dip bioassay method, was determined against the sucking pests, whiteflies, Bemisia tabaci (Gennadius) and thrips, Thrips tabaci Lindeman collected from cotton fields of Tamil Nadu Agricultural University (TNAU), Coimbatore. Based on the LC50 values of respective chloronicotinyl compounds, the order of toxicity was found to be acetamiprid > imidacloprid > thiamethoxam > thiacloprid (B. tabaci) and imidacloprid > thiamethoxam > thiacloprid > acetamiprid (T. tabaci). The respective LC95 values were 11.092, 29.653, 5.055 and 16.034 ppm against whiteflies and 2.876, 12.896, 13.139 and 11.884 ppm against thrips for imidacloprid, thiamethoxam, acetamiprid and thiacloprid, respectively.