Host use patterns of Culicoides spp. biting midges at a big game preserve in Florida, U.S.A., and implications for the transmission of orbiviruses.

Culicoides spp. biting midges (Diptera: Ceratopogonidae) are vectors of pathogens that have a significant economic impact on the livestock industry. White-tailed deer (Odocoileus virginianus), a farmed species in the U.S.A., are susceptible to two Culicoides spp. borne orbiviruses: bluetongue virus and epizootic haemorrhagic disease virus. Elucidating host-vector interactions is an integral step in studying disease transmission. This study investigated the host range of Culicoides spp. present on a big game preserve in Florida on which a variety of Cervidae and Bovidae freely roam. Culicoides were captured with Centers for Disease Control and Prevention (CDC) miniature light traps run twice weekly on the preserve for 18 consecutive months (July 2015-December 2016). Host preference was quantified through forage ratios, based upon PCR-based bloodmeal analysis of Culicoides spp. and overall animal relative abundance on the preserve. Culicoides stellifer preferentially fed on Cervus spp. and fallow deer (Dama dama) and displayed a relative avoidance of Bovidae and white-tailed deer. Culicoides debilipalpis preferred white-tailed deer and avoided all Bovidae. Culicoides pallidicornis and Culicoides biguttatus showed preferences for white-tailed deer and Père David's deer (Elaphurus davidianus), respectively. These results add to current knowledge of preferred hosts of Florida Culicoides spp. and have implications for the spread of orbiviruses. Copyright © 2018 John Wiley & Sons, Ltd.

Comparison of ectoparasite communities of sylvatic and urban wild mesomammals and unowned community cats in north-central Florida.

The adaptation of wildlife species to urban environments can drive changes in the ecology of ectoparasites and vector-borne disease. To better understand ectoparasite dynamics in an urban environment, we investigated the ectoparasite communities of 183 sylvatic and urban opossums and raccoons captured across four seasons at a rural research station and within the city of Gainesville, FL, and of 115 community cats from the Gainesville, FL area. Amblyomma americanum (L.) (Acari: Ixodidae), Dermacentor variabilis (Say), and Ixodes texanus Banks were collected from raccoons, A. americanum, D. variabilis, and Ixodes scapularis Say from opossums, and A. americanum from cats. Few ticks were collected from urban animals, although species richness of ectoparasites was similar between urban and sylvatic habitats. Ctenocephalides felis (Bouché) (Siphonaptera: Pulicidae) was collected from all sampled host species, but was particularly abundant on opossums. Additionally, Orchopeas howardi (Baker) (Siphonaptera: Ceratophyllidae) was collected from raccoons, and O. howardi and Xenopsylla cheopis (Rothschild) (Siphonaptera: Pulicidae) from opossums. Only raccoons were infested with raccoon lice, and only cats were infested with cat lice. Primarily opossums were infested with mites. Ectoparasite community composition varied by habitat, host species, and season; seasonal variation in ectoparasite communities differed between the sylvatic and urban habitats. While urban mesomammals did not appear to play an important role in supporting tick populations in an urban habitat, urban opossums appear to serve as an alternate host for large numbers of cat fleas, which may be an important consideration for treatment and control efforts against ectoparasites of companion animals.

Genetic diversity and fitness in black-footed ferrets before and during a bottleneck.

The black-footed ferret (Mustela nigripes) is an endangered North American carnivore that underwent a well-documented population bottleneck in the mid-1980s. To better understand the effects of a bottleneck on a free-ranging carnivore population, we used 24 microsatellite loci to compare genetic diversity before versus during the bottleneck, and compare the last wild population to two historical populations. We also compared genetic diversity in black-footed ferrets to that of two sibling species, the steppe polecat (Mustela eversmanni) and the European polecat (Mustela putorius). Black-footed ferrets during the bottleneck had less genetic diversity than steppe polecats. The three black-footed ferret populations were well differentiated (F(ST) = 0.57 +/- 0.15; mean +/- SE). We attributed the decrease in genetic diversity in black-footed ferrets to localized extinction of these genetically distinct subpopulations and to the bottleneck in the surviving subpopulation. Although genetic diversity decreased, female fecundity and juvenile survival were not affected by the population bottleneck.