|Moon, Roger - UNIV OF MINNESOTA|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 16, 2008
Publication Date: July 1, 2009
Citation: Geden, C.J., Moon, R.D. 2009. Host ranges of gregarious muscoid fly parasitoids: Muscidifurax raptorellus (Kogan and Legner) (Hymenoptera:Pteromalidae), Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae), and Trichopria (Hymenoptera: Diapriidae). Environmental Entomology. 38(3):700-707. Interpretive Summary: Biological control is an important component of integrated management systems for flies associated with livestock, poultry and horses. Parasitic wasps are among the most important biocontrol agents for flies, and there are several commercial insectaries that provide these wasps to farmers. All of the commercially available wasps attack the fly at the same stage in its development and in similar habitats. There is a need for new biocontrol agents that would target a weak link in the fly’s biology that is not being attacked by our native species. This study was conducted by a scientist at USDA’s Center for Medical, Veterinary and Agricultural Entomology in Gainesville (Florida) and a collaborator at the University of Minnesota as part of a larger effort to discover novel biocontrol agents for flies. Two exotic species of wasps were compared with a species that is commonly sold for fly control in the U.S. for their ability to kill and reproduce on four economically important fly species (house fly, stable fly, horn fly, and black dump fly) and a blow fly that commonly occurs around farms. The authors found that the exotic species (Trichopria nigra and Tachinaephagus zealandicus) appeared to be promising biocontrol agents against major pest fly species, especially horn flies and stable flies.
Technical Abstract: Attack rates, progeny production, sex ratios and host utilization efficiency of Muscidifurax raptorellus (Kogan and Legner) (Hymenoptera: Pteromalidae), Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae), and Trichopria nigra (Nees) (Hymenoptera: Diapriidae) were evaluated in laboratory bioassays with five dipteran hosts: house fly (Musca domestica L.), stable fly (Stomoxys calcitrans L.), horn fly (Haematobia irritans [L.]), black dump fly (Hydrotaea aenescens [Weidemann]) (Diptera: Muscidae) and a flesh fly (Sarcophaga bullata Parker) (Diptera: Sarcophagidae). M. raptorellus killed and successfully parasitized all five host species and produced an average 2.6 parasitoid progeny from each host. Host attack rates were highest on stable fly and lowest on horn fly; there were no differences among hosts in the total number of progeny produced. T. zealandicus killed larvae of all fly host species in similar numbers, but parasitism was most successful on H. aenescens and S. bullata and least successful on horn fly and house fly hosts. Significantly more parasitoid progeny emerged from S. bullata (10.2 parasitoids per host) than the other hosts; only 2.5 progeny were produced from parasitized horn fly hosts. Most of the killed puparia that produced neither adult flies nor parasitoids (“duds”) contained dead parasitoids; in house fly, stable fly and horn fly hosts, >30% of these dudded pupae contained adult wasps that failed to eclose. T. nigra successfully parasitized pupae of all host species except house fly and was most successful on stable fly. Significantly more parasitoid progeny emerged from S. bullata (30.6 parasitoids per host) than the other hosts; only 5.7 progeny were produced from horn fly hosts.