|Moon, Roger - UNIV OF MINNESOTA|
|Butler, Jerry - UNIV OF FLORIDA|
Submitted to: International Symposium on Biological Control of Arthropods
Publication Type: Abstract Only
Publication Acceptance Date: April 2, 2005
Publication Date: September 11, 2005
Citation: Geden, C.J., Moon, R.D., Butler, J.A. 2005. Host ranges of six solitary filth fly parasitoids (hymenoptera: pteromalidae, chalcididae) from Florida, Eurasia, Morocco and Brazil. International Symposium on Biological Control of Arthropods. Davos, Switzerland. Sept 12-15, 2005. Technical Abstract: Pupal parasitoids are among the most important and common natural enemies of filth flies associated with animals and humans. Augmentative releases of parasitoids can provide satisfactory suppression of fly populations, but in many cases parasitoid releases have had little impact on fly populations or parasitism levels. Although the factors that determine success of augmentative releases are unclear, failures may be due to an imperfect understanding of how to match candidate parasitoid species with target pests and breeding conditions. A better understanding of niche characteristics of parasitoid species could assist in the process of matching parasitoid species with release sites. Different parasitoid species have been evaluated in recent years with regard to temperature-dependent attack rates, development time, manure moisture preferences, and the effect of habitat type and depth on foraging behavior. Host range is another niche characteristic that may vary among species of fly parasitoids. Most of the available literature on muscoid fly parasitoids has involved trials with house flies and stable flies. By comparison, information on parasitism of other species such as the horn fly (Haematobia irritans) is limited, and mostly deals with field surveys of flies in various locations. The objectives of this present study were to compare parasitoid attack rates and progeny production on different host species and to determine whether there were distinct differences among parasitoid strains from different locations. Attack rates, progeny production, sex ratios and host utilization efficiency of Muscidufurax raptor Girualt and Sanders, Spalangia cameroni Perkins, S. endius (Walker), S. nigroaenea Curtis, S. gemina Boucek (Hymenoptera: Pteromalidae) and Dirhinus himalayanus (Hymenoptera: Chalcididae) 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. raptor, S.cameroni, and S. endius readily attacked and produced progeny on all five host species, with substantially lower production from S. bullata than from the muscid hosts. Rates of host attacks by S. nigroaenea and S. gemina were similar on house fly, stable fly and black dump fly hosts, with lower rates on horn fly; almost no progeny were produced by S. nigroaenea on S. bullata hosts. D. himalayanus, a large-bodied chalcidid parasitoid, had highest rates of host attacks and progeny production on S. bullata and H. aenescens, followed by stable fly and house fly hosts; very few progeny were produced by this species on horn fly hosts. Overall differences among different geographic strains of parasitoids (from Russia, Kazkhstan and Florida) were generally small, although the Florida strain of M. raptor was superior to the two Eurasian strains. The results with horn fly hosts support field survey data suggesting that several of these species may be promising biological control agents for this pest.