The Influence Of Coumaphos On Enzyme Activities Of Antheraea Pernyi And Blepharipa Tibialis Chao

Antheraea pernyi is an important economic insects in northern China. Blepharipa tibialis (Chao) is a devastating parasite of Antheraea pernyi, often resulting in significant decline in yield and quality of spring silkworm. The Blepharipa tibialis control is special and can not be in the pupa stage and adult stage. The larvae parasites in the body of Antheraea pernyi and thus protected by Antheraea pernyi, so the control chemicals must pass through Antheraea pernyi and then act on Blepharipa tibialis. Therefore, the control insecticide must have high selective control. Mie Can Ying has the selective killing effect between Antheraea pernyi and Blepharipa tibialis, but the selective mechanism has not been clear. The selective mechanism may due to the selective toxicity, may also due to the differential body size.To the above problem, we did the following research. The researches included the influence of coumaphos (the active ingredient of Mie Can Ying) on enzymes activity of Antheraea pernyi, the influence of Blepharipa tibialis parasitization on enzymes activity of Antheraea pernyi and the enzyme activity differential between Antheraea pernyi and Blepharipa tibialis, etc. And studied the activity differential of insecticide resistance related acetylcholinesterase (AChE), detoxification enzymes and phenoloxidase (PO), to clear off the enzyme fundamentals of the selective action of Mie Can Ying. Following are the results:1. The influence of coumaphos on the enzyme activities of Antheraea pernyi showed that: there were no significant differences between the treatmented group and the control group on AChE and cytochrome P450 (CYP450) activities of fat body, on AChE and glutathione S-transferase (GST) activities of hemolymph, on PO and GST activities of head. And There were also no significant differences between the treatmented group and the control group on in vitro inhibition rates of CYP450, carboxylic esterase (CarE) and PO of fat body and the haemolymph, on in vitro inhibition rates of AChE and CYP450 of the head, on in vitro inhibition rates of AChE of the haemolymph.2. The influence of Blepharipa tibialis parasitization on enzyme activities of Antheraea pernyi showed that:there were no significant differences between the Blepharipa tibialis parasitic and the non parasitic Antheraea pernyi on activities and in vitro inhibition rates with coumaphos of AChE, GST, CYP450, and PO of head, fat body and hemolymph. There were significant differences on CarE activity of head and CarE activity of hemolymph. The fat body CarE activity was not significant different. There were no significant differences between the Blepharipa tibialis parasitic and the non parasitic Antheraea pernyi on in vitro inhibition rates with coumaphos of CarE activity. 3. Comparation of the enzyme activities between Antheraea pernyi and Blepharipa tibialis shows that:there were vary activity difference between Antheraea pernyi and Blepharipa tibialis on activity of the target enzyme (AChE), detoxification enzymes (GST, CYP450, CarE) and PO. There were no significant differences between Antheraea pernyi and Blepharipa tibialis on in vitro inhibition rates with coumaphos of GST,CYP450 and PO, and on AChE. But, the in vitro inhibition rates of CarE were significantly different. There are significant differences on in vitro inhibition rates with coumaphos of AChE of Antheraea pernyi's head and Blepharipa tibialis, but there were no significant differences on AChE of Blepharipa tibialis and Antheraea perny'fat body and Blepharipa tibialis.4. Comparison on enzyme activities of Blepharipa tibialis of different geographical populations showed that:there are some differences among five Liaoning Province geographic populations on activites and in vitro inhibition rates with coumaphos of Blepharipa tibialis's target enzyme (AChE), detoxification enzymes (GST, CYP450, CarE) and PO activity. Thus, we presumed that the population of Fengcheng city has relatively higher resistance to coumaphos, Wafangdian population has relatively lower resistance to coumaphos.In summary, coumaphos and Blepharipa tibialis parasitizion had little effect on the enzyme activities of Antheraea pernyi. There were significant differences between Antheraea pernyi and Blepharipa tibialis on enzyme activity. There were some differences among different geographical populations on enzyme activity of Blepharipa tibialis. So the enzyme activity difference between Antheraea pernyi and Blepharipa tibialis was the base of the selective toxicity of Mie Can Ying.