Study on the Parasitic Characteristics ofDiachasmimorpha longicaudata (Ashmead) onDifferent Insecticide-resistant Strain Hosts

【Objective】The study was to clarify the selection tropism of Diachasmimorpha longicaudata on Bactrocera dorsalis Hendel with different resistance levels and the effects of insecticide-resistant host stains on the development characteristics of D. longicaudata.【Method】By means of“Y”-tube olfactometer testing and choice test, the behaviour response and parasitic capacity of D. longicaudata to three kinds of B. dorsalis Hendel insecticideresistant strains were determined, and the larval development of D. longicaudata on these three strain hosts werealso investigated by biological observation test.【Result】The results showed that D. longicaudata had no significant selection tropism to B. dorsalis Hendel strains that resistant to trichlorphon, beta-cypermethrin and abamectin. Similarly, there was no significant difference in the parasitic number of D. longicaudata to different B. dorsalis Hendel resistant strains. The D. longicaudata on different resistant host strains showed sex differences in larval developmental duration, viz., there was no significant difference in the larval development duration of female wasps on different test host strains, while the developmental duration of male wasps on high resistant strains was significantly shorter than that on middle resistant strains and regular strains.【Conclusion】Different insecticide-resistant strains of oriental fruit fly had no significant effect on the parasitic rate of D. longicaudata, but showed significant influence on the developmental duration of male wasps. The test result can provide a theoretical basis for the effective control of oriental fruit fly by the use of the D. longicaudata.