Filth fly parasitoid (hymenoptera: pteromalidae) monitoring techniques and species composition in poultry layer facilities

Authors: Pagac, Alexandra; Geden, Christopher - Chris; BURGESS, EDWIN - University Of Florida; RIGGS, MONTANA - Pennsylvania State University; MACHTINGER, ERIKA - Pennsylvania State University

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2022
Publication Date: 9/20/2022
Citation: Pagac, A.A., Geden, C.J., Burgess, E.R., Riggs, M.R., Machtinger, E.T. 2022. Filth fly parasitoid (hymenoptera: pteromalidae) monitoring techniques and species composition in poultry layer facilities. Journal of Medical Entomology. 59(6):2006-2012. https://doi.org/10.1093/jme/tjac124.
DOI: https://doi.org/10.1093/jme/tjac124

Interpretive Summary: Filth flies such as house fly and stable fly are among the most important pests of animal agriculture throughout the world. Fly control has long centered on the regular use of insecticides that are applied to premises, the animals themselves, or in baits. Insecticide resistance by the fly has made it increasingly difficult to these pests in this way. The most effective alternative to insecticidal control is the release of parasitic wasps that attack the fly while it is in the pupal stage. In this study, scientists at Pennsylvania State University, USDA-ARS-CMAVE (Gainesville, FL), and the University of Florida conducted a survey of parasitoids occurring naturally on poultry farms. The most common species belonged to the genera Spalangia and Trichomalopsis. A comparison of survey methods revealed that the most accurate results were obtained by placing larvae in a natural substrate and allowing them to pupate before being placed in the field as sentinels.

Technical Abstract: Muscid flies, especially house flies (Musca domestica L, Diptera: Muscidae), are a major pest of poultry facilities, particularly those specializing in egg production for human consumption. Biological control of muscid flies in the form of augmentative releases of pteromalid wasps has gained increased attention in recent years. Knowing which pteromalid species are present in a specific area could produce more effective results from these releases. To this end, this project had two goals. The first was to survey parasitoid populations in poultry layer facilities in central and southeastern Pennsylvania. The second was to confirm the accuracy of a new collection device for surveying parasitoid wasp populations. Two genera, Spalangia and Trichomalopsis, were collected over the course of the survey from June until September. Overall, the species collected in order of most to least common were Spalangia cameroni, Spalangia nigroaenea, Trichomalopsis spp., and Spalangia endius. Differences were found in the presence and prevalence of these species between locations and the month of collection. During field collection for this survey a new parasitoid collection device, which uses buried hosts to attract more burrowing parasitoids than surface searching parasitoids, was compared to a more traditional method, the sentinel bag. The new parasitoid device consisted of a plastic container with a screened lid that contained rearing media and third instar house fly larvae. A clear difference was seen between the two methods, with the new device collecting a higher proportion of Spalangia spp. and the sentinel bag collecting more of the gregarious Trichomalopsis.spp. This suggests that using this new device alongside the traditional collection method may result in more accurate sampling of pteromalid populations.