Response of Acetylcholinesterase to Insecticides in Reticulitermes chinensis Snyder (Isoptera: Rhinotermitidae)

The subterranean termite Reticulitermes chinensis Snyder is an important pest in China. We determined the inhibition of six selected insecticides to acetylcholinesterase (AChE) extracted from R. chinensis. Our results yielded half maximal inhibitory concentrations (I50) for each of the insecticides to be 3.49 × 10–3 M for methomyl, 3.87 × 10–2 M for phoxim, 2.18 × 10–3 M for triazophos, 1.89 × 10–3 M for profenosos, 1.10 × 10–3 M for malathion, and 4.39 × 10–2 M for omethoate. Furthermore, the inhibitory activity of AChE by the six insecticides was increased with the increase of insecticide concentration from 3.3 × 10–7 to 5 × 10–3 M. These results provide a theoretical basis for the management of R. chinensis.