Deer keds are hematophagous ectoparasitic fliess that primarily feed on cervids. Keds have historically been considered pests of minor medical importance, but pathogens have been detected previously. Because deer keds and ticks can concurrently be found on deer and are actively host-seeking at approximately the same time, it is important to establish the distribution of deer keds, their relationship with their hosts and ticks, and whether they are potential pathogen vectors. We used a combination of passive and active surveillance to elucidate the role of deer keds in traditionally tick-borne disease systems.
Deer ked and tick attachment patterns on white-tailed deer and elk
Little is known about the acquisition and potential for transmission of pathogens found in deer keds; however, tick-deer ked co-feeding transmission is one possible scenario. On-host localization of ticks and deer keds on white-tailed deer was evaluated across several geographical regions of the eastern US to define tick-deer ked spatial relationships on host deer, which may impact the vector-borne disease ecology of these ectoparasites. We conducted a follow-up study looking at elk as potential hosts for deer keds and how the on-host distribution of blacklegged ticks and deer keds on elk may differ from that of white-tailed deer.
Relevant Papers:
Skvarla, M.J., Poh, K.C., Norman, C., Struckhoff, E.D., and Machtinger, E.T. 2023. A comparison of European deer keds (Diptera: Hippoboscidae: Lipoptenacervi (Linnaeus)) and blacklegged ticks (Ixodida: Ixodidae: Ixodesscapularis say) on elk (Cervuscanadensis (Erxleben)) and white-tailed deer (Odocoileusvirginianus (Zimmermann, 1780)) in Pennsylvania. Journal of the Entomological Society of Ontario 154.
Having to sample statewide (and beyond) can be challenging, especially with limited resources, time, and manpower. Therefore, we used a community science approach, supplementing active collection methods, to gather data on the distribution of blacklegged ticks and deer keds in Pennsylvania, as well as establish community collections as a viable and effective method to conduct this research. Our goals were to gather as many specimens from as wide a distribution as possible within Pennsylvania. From this, we produced distribution maps of ticks and deer keds and to test these samples for potential pathogens. We also worked with the hunting communities and surveyed on their current tactics to prevent ectoparasite bites while hunting. All of this information together can help inform outreach and Extension activities to effectively communicate ectoparasite bite prevention for hunters and their animals during the hunting season.
With increasing interest in the importance of deer keds as potential pathogen vectors and the current establishment of ticks as vectors, standardized sampling methods are required that allow researchers to compare ectoparasite burdens on deer across collection events, studies, and geographic areas. Prior to starting this work, there were no standardized methods to collect multiple ectoparasites from deer and other cervids, which can make it difficult to interpret data across different studies. So we established a systematic protocol to sample ectoparasites (including deer keds and ticks) so that we can compare studies globally. We also established a protocol on dissecting salivary glands from deer keds for pathogen testing purposes.