Seven kinds of restricted use environmental pesticides were executed to evaluate the control efficacy of these pesticides for the adults of biting midge, Forcipomyia taiwana with ultra-low-volume spray method. Bioassays showed that, when applied to four different strains of biting midges with recommended concentrations, most dilutions of these restricted use environmental pesticides gave tested adults the low knockdown effects with the KT50 more than 30min. The killing effects of seven pesticides were significantly different for the same strain of biting midges based on the mortalities for 24 hours after treatment. In four tested areas Environmental Pesticide A had the best killing effect among all tested pesticides and 100％ mortality was obtained when its 180-fold recommended dilution was applied to biting midges of four local strains. The efficacies of seven technical grade environmental pesticides (active ingredients) were evaluated. The 100％ mortality for 24 hours after treatment was observed when 360-fold dilution of chlorpyrifos (30％) applied to Da-Keng strain, Taichung and 180-fold dilution applied to Guei-Ren strain, Tainan, respectively. The 40-fold dilution of tetramethrin (5％) had a good knockdown effect and killing effect against Da-Keng strain. The 60-fold dilution of fenvalerate (13.8％) also had a significantly good killing effect in Da-Keng Area. The 200-fold dilution of etofenprox (6.5％) also caused 91.2％ mortality against tested adults in the same area. However, the 200-fold dilution of cypermethrin (25.2％) had no knockdown effect against Zhu-Shan, Da-Keng, and Guei-Ren strains of biting midges. When applied to the three local strains, respectively the 160-fold dilution of permethrin (20％) had a nice knockdown effect and killing effect. The 87.7％ mortality was obtained when the 200-fold dilution of fenitrathion (30％) was applied to Da-Keng strain for 24 hours after treatment. Seven technical grade environmental pesticides were tested against Zhu-Shan, and Da-Keng strains based on the LC50. The results showed that the LC50 for Zhu-Shan strain was higher than those for Da-Keng strain. That was the biting midges of Da-Keng strain was more susceptible than those of Zhu-Shan strain to all tested technical grade environmental pesticides.

Biting,midges,,environmental,pesticides,,control,efficacy,test