Location: Mosquito and Fly Research
2018 Annual Report
Objectives
1. Evaluate the effects of climate change on filth fly populations and their
natural enemies.
1A. House fly management under high temperature conditions.
1B. Verify seasonality, resource preference and range of Stomoxys niger in East Africa.
2. Increase the efficiency of integrated pest management programs by the
development and improvement of traps and behavior-altering surfaces and chemicals.
2A. Identify and develop stable fly optical or chemical attractants which will improve trap efficacy.
2B. Conceive of or develop applications for behavior-altering devices, surfaces and chemicals (e.g., attractants, repellents, and pesticides) for practical use on and around livestock and poultry.
3. Develop management techniques for fly larvae.
3A. Development of more effective larval detection and control techniques for filth flies.
3B. Autodissemination of Insect Growth Regulators (IGR’s) by house flies.
4. Improve biological control techniques for filth flies.
4A. Improved efficacy of Beauveria bassiana by formulating combination products with other agents.
4B. Location of host pupae by filth fly parasitoids.
4C. Improve the quality of commercially available fly parasitoids.
Approach
Objective 1 will investigate and identify methods for management of house flies
under the higher temperatures expected to occur with global warming. It will also
use trapping data to determine risk of introduction of exotic Stomoxys spp. in the U.S.
Objective 2 will develop chemical or optical attractants that will enable traps for stable flies to become more efficient and capture greater numbers of flies. It will also adapt behavior-altering devices, such as pesticide-impregnated fabrics, for different uses, such as attract and kill devices.
Objective 3 will evaluate new methods for determining the presence of sub-surface
immature fly populations in field habitats. It will also further develop methods to allow house flies to spread selected IGRs throughout their habitats.
Ojective 4 will improve the efficacy of a biological control agent by formulating
it with other selected lethal agents. It will also investigate the methods (e.g.,
chemical cues) used by parasitic wasps to locate fly pupae in field habitats.
Finally, we will gain new knowledge on the effects of long-term colonization on the performance of parasitic wasps being released into the field.
Progress Report
Work was completed on the effects of temperature effects on parasitoids. Work on the model remained problematic because of challenges working with legacy software.
Optically attractive materials, including targets, were evaluated in lab and field tests against stable flies. Targets of blue, black, or blue and black cloth were highly attractive, but sticky traps placed adjacent to targets greatly underestimated the numbers of stable flies attracted by targets. Devices to physically capture flies without adhesives were evaluated and found to be ineffective in their preliminary form. Work has been delayed because a major cooperator has been assigned to another job position. Behavior-altering chemicals in fabrics for use around fly traps are being evaluated for their toxic qualities when fly contact is minimal. Results with preliminary tests are promising.
Capture of headspace volatiles produced by fly larvae developing in selected laboratory media or substrates continues but the key cooperator no longer works at our laboratory. Efforts are being made to find a new cooperator who will be willing to continue the work. Results from field tests of pyriproxyfen autodissemination stations conducted on dairy farms in Nebraska and California indicated that flies in the field were reluctant to alight on the stations. Current and future work will shift away from the attractive stations towards releases of treated flies. Work on combining Beauveria bassiana with bacterial pathogens for adult fly control was completed. In a new direction for this sub-objective, the efficacy of B. bassiana was assessed against fly larvae. The GHA strain of this pathogen strain provided nearly 100% larval control when spores were added to larval media 24 hours after placement of eggs. Another new direction for this subobjective was the discovery that the “plant-protecting” bacteria Pseudomonas protegens was virulent for adult house flies, especially when injected. This pathogen was found to be highly virulent for stable fly larvae and moderately virulent for house fly larvae. Cell-free culture broth was as effective as broth containing live bacteria, strongly suggesting that exotoxins account for a substantial part of the virulence. Parasitoid responses to extracts of hosts and host media were weak, and there was no measurable attraction to different fractions of those extracts. Compatibility testing of competing fly parasitoids was completed; making collections of M. raptorellus from Chile was not feasible this year.
Accomplishments
1. Virulence of the fungus Beauveria bassiana and three bacterial pathogens against adult house flies. Microbial house fly control has concentrated on the fungal pathogen Beauveria bassiana. ARS researchers at Gainesville, Florida and researchers at University of Florida, Gainesville, Florida, compared adult fly susceptibility to B. bassiana with the bacteria Photorhabdus temperata, Serratia marcescens, and Pseudomonas protegens. Bacteria killed flies faster than B. bassiana when injected. B. bassiana and P. protegens caused mortality when applied topically. An exotoxin may cause P. protegens mortality. P. protegens killed faster than B. bassiana but with a lower mortality rate. Results suggest that the two pathogens used together would provide better fly control than either of them alone.
2. Non-nutritive house fly bait using artificial sweeteners. The entomopathogenic fungus, Beauveria bassiana, is an effective house fly bait when mixed with sugar. Because this bait takes several days to kill flies, and sugar tends to enable flies to live longer, there are mixed reactions to this bait. ARS researchers at Gainesville, Florida and researchers at Northern Illinois University, DeKalb, Illinois, altered the bait by replacing sugar with the artificial sweeteners, xylitol and erythritol. The sweeteners, used in human foods, have little nutritional value. Flies fed avidly on the sweeteners which effectively delivered B. bassiana to kill flies. Thus fly longevity was not related to the bait. Results open new avenues for using B. bassiana.
3. Autodissemination of pyriproxifen as a method for house fly control. The insect-growth regulator, pyriproxyfen (PPF) prevents fly development past the pupal stage. ARS researchers at Gainesville, Florida and researchers at University of Haifa, Haifa, Israel, used flies to apply PPF to their egg-laying sites by exposing active-coated flies at different proportions in lab tests with animal manures. Just 10-20% of PPF-coated flies was enough to get 90% control levels in most U.S. manures. In Israel, mortality was low-medium in cow manure but in poultry manure 10% PPF-coated flies produced high mortality. Results confirm that autodissemination of PPF using the active coating concept may be practical depending on manure type and target population size.
4. The Knight Stick sticky fly trap surrounded by hot grass did not affect the numbers of flies captured. Knight Stick (KS) sticky fly traps surrounded by protective squares of electric fence placed close to animal hosts capture 6-9 X more stable flies. ARS researchers at Gainesville, Florida and researchers at Smithsonian’s National Zoological Park (SNP), Washington, District of Columbia, evaluated other types of enclosure materials, namely hot grass, which conducts electric current but is practically invisible from a distance. Hot grass performed well and could be used instead of standard fencing wire with no reduction in effectiveness. This technology can be used by zoos, but also by beef and dairy cattle and equine industries.
Review Publications
Hogsette, Jr, J.A., Foil, L.D. 2018. Blue and black cloth targets: Effects of size, shape and color on stable fly (L.) (Diptera: Muscidae) attraction. Journal of Economic Entomology. 111:974-979. doi:10.1093/jee/toy015.
Hogsette, Jr, J.A., Ose, G.A. 2017. Improved capture of stable flies (Diptera: Muscidae) by placement of Knight Stick sticky fly traps protected by electric fence inside animal exhibit yards at the Smithsonian’s National Zoological Park. Journal of Zoo Biology. doi:10.1002/zoo.21382.
Kline, D.L., Hogsette, Jr, J.A., Rutz, D.A. 2018. A comparison of the Nzi, Horse Pal and Bite-Lite H-traps and selected baits for the collection of adult Tabanidae in Florida and North Carolina. Journal of Vector Ecology. 43(1):63-70. doi:10.1111/jvec.12284.
Hogsette, Jr, J.A. 2018. Evaluation of cyanarox insecticidal bait against stable flies (Diptera: Muscidae). Journal of Economic Entomology. doi:10.1093/jee/toy191.
Johnson, D.M., Rizzo, E., Taylor, C.E., Geden, C.J. 2017. Effect of host decoys on the ability of the parasitoids Muscidifurax raptor and Spalangia cameroni to parasitize house fly (Diptera: Muscidae) puparia. Florida Entomologist. 100:444-448.
Biale, H., Geden, C.J., Chiel, E. 2017. Effects of pyriproxifen on wild populations of the house fly, Musca domestica, and compatibility with its principal parasitoids. Pest Management Science. doi:10.1002/ps.4638/epdf.
Sanscrainte, N.D., Arimoto, H., Waits, C.M., Li, L.Y., Johnson, D.M., Geden, C.J., Becnel, J.J., Estep, A.S. 2018. Reduction in Musca domestica fecundity by dsRNA-mediated gene knockdown. PLoS One. 13(1):e0187353. doi:10.1371/journal.pone.0187353.
Burgess, E.R., Johnson, D.M., Geden, C.J. 2018. Mortality of the House Fly (Diptera: Muscidae) after exposure to combinations of Beauveria bassiana (Hypocreales: Clavicipitaceae) with the polyol sweeteners Erythritol and Xylitol. Journal of Medical Entomology. 55(5):1237-1244.
