关键词: 德国小蠊, 抗药性, 增效作用

Abstract: The sensitivity of four field strains (ZAU.JC.DH and HZ) of Blettella germanica (L.)to permethrin, deltamethrin, cypermethrin, chlorpyrifos, and propoxur was tested with a topical application method to estimate LD₅₀.The results indicated a high level of resistance in these strains to pyrethroids, especially to permethrin.The LD₅₀ resistance ratios (RRS) for permethrin were 36.6, 59.4,38.6 and 69.1 for ZAU, JC, DH and HZ, respectively.The field strains had low levers of resistance to chlorpyrifos and propoxur; the LD₅₀ RRs for chloxpyrifos were 2.2, 2.4, 2.1 and 2.0 for ZAU, JC, DH and HZ, respectively.Studies were conducted (in vivo) on the HZ strain to determine the synergistic effect on permethrin by three metabolic inhibitors: piperonyl butoxide (PBO), triphenyl phosphate (TPP); and diethyl maleate (DEM).The sgnergistic effect on the LD₅₀ RR for PBO, TPP, DEM were 3.69, 1.76 and 1.16 times, respectively.These data indicate that the mechanism for pyrethroid resistance in the HZ strain be aaseciated with mixed function oxidases (MFO) and carboxylesterases (CarE), and probably not with glutathione-s-transferase (GST）.