In order to study the insecticidal activity of methoxyfenozide ( RH-2485 ) against the larvae of Lymantria dispar ,the pesticide bioactivity of the chemical against the different instar larvae of L. dispar and its effect on the activities of detoxifying enzymes of the insect were assayed using leaf film method, and the expression of proteins in different tissues of the larvae were detected with SDS-PAGE. The results showed that methoxyfenozide had a high toxicity against the larvae,especially 2nd instar and 3rd instar, and the toxicity was obviously different with different larva instars. The activities of detoxifying enzymes, such as carboxylesterase ( CarE ) , MFO O-demethylase ( MFOD ) and glutathione S-transfer (GST) , in the 2nd , 4th , 6th instar larvae were significantly induced or inhibited by the methoxyfenozide treatment. The impact of methoxyfenozide on these enzymes was significantly different at different treatment time. After the 4th instar larvae were fed with methoxyfenozide, the protein expression pattern in the hemolymph ,midgut and epidermis was different from that in the control. The effect of methoxyfenozide on proteins in the hemolymph and midgut was obvious in 12 h and 24 h, whereas the effect on protein expression in epidermis tissue was more significant in 48 h. These results indicated that methoxyfenozide as a non-steroidal ecdysone had a higher biological activity against L. dispar, and the major detoxifying enzymes in the insect body were significantly interfered, showing that methoxyfenozide had a high toxic effect against L. dispar. The specific proteins were produced in the hemolymph , midgut and epidermal tissue, which might interfere with the normal physiological metabolism of insects and epidermal formation.%为研究甲氧虫酰肼(RH-2485)对舞毒蛾幼虫的杀虫活性,采用叶片药膜法测定该药剂对舞毒蛾不同龄期幼虫的生物活性及对其体内解毒酶活性的影响,并通过SDS-PAGE对舞毒蛾幼虫不同组织的蛋白质表达进行检测.结果表明:甲氧虫酰肼对舞毒蛾2～6龄幼虫均表现出较高活性,其中对2,3龄幼虫毒性最强,说明甲氧虫酰肼对舞毒蛾幼虫的影响存在明显的龄期差异.该药剂对2,4,6龄幼虫体内的羧酸酯酶、多功能氧化酶O -脱甲基和谷胱甘肽S-转移酶等主要解毒酶存在显著影响,表现为诱导、抑制作用；在不同的处理时间,对这些酶的影响存在明显差异.舞毒蛾4龄幼虫经甲氧虫酰肼处理后,血淋巴、中肠及表皮组织中均发现与对照组有差异的蛋白,其中处理12h和24 h时,对血淋巴和中肠组织中的蛋白质影响比较明显,48 h后,对表皮组织中的蛋白质表达的影响较为显著.甲氧虫酰肼作为非甾醇类蜕皮激素竞争物中的新型化合物,能干扰舞毒蛾幼虫体内主要解毒酶活性,诱导血淋巴、中肠和表皮组织中产生特异蛋白,从而影响舞毒蛾正常的生理代谢,起到毒杀作用,可有效防治舞毒蛾.
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