Location: Arthropod-borne Animal Diseases Research
2023 Annual Report
Accomplishments
1. Microbes, soil properties and animal disturbance affect the presence of biting midges. Biting midges are tiny insects that spread diseases to livestock, causing significant economic losses. Their larvae grow in semi-aquatic habitats like the shorelines of ponds and springs, but what exactly attracts midges to these places is not known. Understanding the factors that influence where midge larvae are found can help scientists and farmers develop better strategies to control their populations and therefore the diseases they transmit. ARS researchers in Manhattan, Kansas, in collaboration with Kansas State University, studied soil microbiomes, soil chemistry and midge presence in ponds and springs with different animal grazing activities. The types of habitats, grazing by animals like cattle or bison, and soil chemical properties influenced both the types of microbes that were present and whether midges would be found. Certain groups of microorganisms were found to either increase or decrease in the presence of midges, which provides important clues about the relationship between microbes and midge survival. Researchers can further explore how manipulating microbes or other aspects of the habitat can lessen or even inhibit usage by midges, which will help in managing midge-transmitted diseases.
2. House flies from Kansas, Oklahoma and Texas dairy cattle operations carry human and cattle pathogens. House flies flourish in dairy cattle operations where they have unlimited access to food and reproductive sites. Prior studies demonstrated that house flies are reservoirs and potential transmitters of bacteria both within the production operation and off site to nearby human habitation. ARS researchers in Manhattan, Kansas, collaborated with researchers at Oklahoma State University and Texas A&M University to determine the bacterial communities carried within female house flies collected from dairy cattle operations in Kansas, Oklahoma, and Texas across 4 months in 2020. Across all sites, house flies carried human pathogens that cause foodborne illness and some cattle pathogens associated with pink eye and bovine respiratory disease. Interestingly, the types of bacteria within the flies represented a snapshot of the bacteria found in their surrounding environment. These findings show that house flies not only are a problem in carrying and disseminating pathogens, but also can help us monitor threats to both livestock and human health at these cattle operations.
3. House flies have a unique mechanism for regulating immune genes that are consistently activated. House flies have evolved an impressive immune system to adapt to their filth-associated lifestyle. Unlike other insects, house flies possess a multitude of genes coding for antimicrobial defenses, providing them with a superior repertoire. The activation of these defense genes, including where, when and how much product is made, is carefully regulated to ensure optimal protection without squandering valuable energy resources. ARS scientists in Manhattan, Kansas, in collaboration with researchers from the University of Houston, discovered that some immune genes in flies are activated on an as-needed basis through classical immune response mechanisms seen among other insects. However, other genes which require constant activation use a mechanism different from these typical immune-induction pathways. This unique mechanism could play a crucial role in the fly's survival and potentially serve as a vulnerability that could be targeted for controlling flies in the future.
Review Publications
Neupane, S., Davis, T.M., Nayduch, D., McGregor, B.L. 2023. Habitat type and host grazing regimen influence the soil microbial diversity and communities within potential biting midge larval habitats. Environmental Microbiome. 18(1):5-21. https://doi.org/10.1186/s40793-022-00456-8.
Nayduch, D., Neupane, S., Pickens, V., Purvis, T.J., Olds, C. 2023. House flies are underappreciated yet important reservoirs and vectors of microbial threats to animal and human health. Microorganisms. 11(3). Article 583. https://doi.org/10.3390/microorganisms11030583.
Neupane, S., Hall, B., Brooke, G.M., Nayduch, D. 2022. Sex-specific feeding behavior of adult house flies, Musca domestica L. (Diptera: Muscidae). Journal of Medical Entomology. 60(1):7-13. https://doi.org/10.1093/jme/tjac161.
Asgari, D., Saski, C.A., Meisel, R.P., Nayduch, D. 2022. Identification of constitutively-expressed immune effectors in the house fly (Musca domestica L.) and the transcription factors that regulate them. Insect Molecular Biology. 31(6):782-797. https://doi.org/10.1111/imb.12804.
Swanson, D.A., McGregor, B.L. 2022. Life history metrics for Culex tarsalis (Diptera: Culicidae) and Culicoides sonorensis (Diptera: Ceratopogonidae) are not impacted by artificial feeding on defibrinated versus EDTA-treated blood. Journal of Medical Entomology. 60(1):224-227. https://doi.org/10.1093/jme/tjac171.
