抄録
The effect of multiple parasitism of an endoparasitic wasp, Dacnusa sibirica, on several life history traits of two ectoparasitic wasps, Diglyphus isaea and Hemiptarsenus varicornis was examined. Two types of Liriomyza trifolii larvae were used as hosts. One type was a larva parasitized by D. sibirica and the other was a healthy one. Individuals of one of the two types of hosts were exposed to female adults of the two species of ectoparasitic wasps. The adult handling time was measured and the developmental period, mortality in nymphal stages, emerged sex ratio, and the length of hind tibia of newly emerged D. isaea and H. varicornis wasps were surveyed. We found the parasitization by D. sibirica had no effect on the life history traits of the two ectoparasitic wasps. Thus, we conclude that the two ectoparasitoids did not decrease the activity of parasitization under the existence of D. sibirica.
