Arthropod faunal composition on Kentucky equine premises

A total of 39 arthropod species representing the families Muscidae, Chloropidae, Tabanidae, Simuliidae, Culicidae and Ixodidae was collected from Kentucky horse farms using dry ice-baited canopy traps, light traps, water samples, tick drags, and animal inspections during late April to mid-October 1987 and 1988. 33 species were collected from canopy traps, consisting of 74.3% muscids (Stomoxys calcitrans and Musca autumnalis), 16.7% chloropids (Hippelates spp.), 5.0% simuliids (Prosimulium magnum, Simulium venustum, S. vittatum and S. decorum), 3.8% tabanids (8 species of Chrysops, of which C. callidus was the most abundant, 2 of Hybomitra, of which H. lasiophthalma was the most abundant, and 11 of Tabanus, including T. quinquevittatus and T. sackeni), and 0.2% mosquitoes (5 species, including Aedes triseriatus and Psorophora columbiae). Light traps attracted 8 culicid species (including Culex restuans) and water samples yielded 3. One ixodid species (Dermacentor variabilis) was collected with drags, and animal inspections yielded 2 muscids (M. autumnalis and Haematobia irritans) and 2 ticks (D. variabilis and Ixodes cookei, the latter on a dog). Comparison of species assemblages among farms and across years using multivariate principal component analysis (PCA) yielded 3 distinct principal components, and PCA scores for each farm per year were correlated with biotic and abiotic environmental factors and management practices. The proximity to cattle herds was the best predictor of similarity in species assemblages among farms, reflecting the high percentage of muscid species collected. Poor management practices were partially responsible for proportionally larger populations of culicids, ixodids and muscids on some farms.