A laboratory comparison of the effect of acetone-diluted chlorfenapyr standards with a commercial suspension formulation on four domestic mites (ACARI: Astigmata)

Chlorfenapyr is a pesticide that is widely used to control herbivorous mites and insects. The commercial application of chlorfenapyr is focused on the control of urban pests (cockroaches, bed bugs and ants), but the toxicity of chlorfenapyr to domestic mites is poorly understood. Here, the toxic effect of chlorfenapyr to domestic mites was tested in an impregnated filter paper laboratory test. Chlorfenapyr, either as an analytic standard or commercial suspension concentrate (SC) formulation, was applied to the glass bottles with filter paper, and the mortality of the mites (Acarus siro, Lepidoglyphus destructor, Dermatophagoides pteronyssinus and D. farinae) was evaluated after 24h of exposure. There were no significant differences in the toxicity to the mites between the SC and the analytical standard. The chlorfenapyr in both formulations was toxic to L. destructor and D. pteronyssinus, D. farinae. The LC95 ranged from 20 to 304g cm(-2). Lower toxicity was observed with A. siro, and LC values were not estimated.