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item Riddick, Eric

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2002
Publication Date: 7/20/2003
Citation: Riddick, E.W. 2003. Effects of parasitoid density and arena size on progeny production of anaphes iole girault (hymenoptera:mymaridae). Journal of Entomological Science.

Interpretive Summary: Fairyflies represent a family of parasitic wasps that commonly deposit their eggs inside the eggs of other insects. Some species, such as Anaphes iole, serve as important natural enemies of plant bugs, especially the western tarnished plant bug, Lygus hesperus. Research is underway to discover efficient techniques for mass propagating A. iole for releases into the field or greenhouse. Laboratory experiments were conducted to see if the density of females searching and depositing their eggs in the same patch of host eggs had any effect on the total number of hosts parasitized in 24 hours. The results of this study revealed that female parasites did not interfere with each other to any significant degree when there was a superabundance of host eggs available to parasitize. Arena size was not so important. These results suggest that A. iole can be reared on a large scale. This study is of value to scientists in universities, government service, and private industry interested in using natural enemies to control crop pests.

Technical Abstract: Anaphes iole Girault is a native, solitary egg parasitoid of Lygus spp. in North America. This study examined the effects of A.iole female density and arena size on progeny production under laboratory conditions. Production increased by a factor of 2.1 as parasitoid density increased from 5 to 10 and from 10 to 20 A.iole females per 8.3L arena (rearing cage) with a large host patch containing from 1,500 to 2,000 eggs of Lygus hesperus Knight (Heteroptera: Miridae). Sex ratios of mature progeny did not differ significantly between parasitoid densities of 10 versus 20 females. Arena size (0.95, 1.7, 3.8, or 7.95 L cages) had no effect on progeny production when 20 females were confined to cages containing a large host patch. This research suggests that little or no measurable interference occurs between ovipositing females on a large host patch and that the presence of a superabundance of putative hosts could be more important than arena size for efficient in-vivo production of A. iole.