甲胺磷和溴氰菊酯的联合生物活性及其作用机制初探

BIOLOGICAL ACTIVITY AND MODE OF ACTION OF JOINT TREATMENT OF DELTAMETHRIN AND METHAMIDOPHOS

采用滤纸药膜残留法测定了甲胺磷和溴氰菊酯联合应用对玉米螟三龄幼虫的触杀活性。ＬＣ５０和ＬＣ９０剂量水平的活性联合作用分析均显示，该组合具显著联合增效作用。蜚蠊中枢神经自发性复合突触后电位（ｓＥＰＳＰｓ）记录结果表明，这两种药物联合处理后突触电位排放显著增强，说明这两种药物神经毒理的协同效应可能是生物活性增效的重要机制之一。

Activities of the joint treatment of methamidophosdeltamethrin on the Asian cornborer ( Ostrinia furnacalis ) were tested in laboratory. The cotoxic coefficient (CTC) values of the mixture calculated on LC 50 or LC 90 revealed the significant synergistic action. Neurotoxic effects of the joint treatment on the spontaneous excitary post synaptic potentials (sEPSPs) at the cercalgiant fiber synapse located within the sixth abdominal ganglion of the American cockroach ( Periplenata americana ) were studied by using extracellular recording method. Low frequency single or continuous sEPSP spides were detected in the treatment of the methamidophos or deltamethrin. However, high frequency overshotings of sEPSP were recorded in the joint treatment, the frequency reaching 0.050.15 times/ms, range of the spides being 2.53.2 mV. The phenomenon might suggest that the neurophysiological joint action be one of the major mechanisms of synergistic biological activity of the insecticide combination.