Feeding Behavior and Host Preferences of Some Black Flies (Diptera:Simuliidae) in Wisconsin1

Abstract

A rapid method for capturing simuliids attracted to and feeding on hosts is described. Engorged and nonengorged specimens readily entered the trap. The method was superior to human visual observation in detecting black fly feeding activity on avian hosts. The blood-sucking females were divided into two categories, those feeding on birds (ornithophilic) and those feeding on mammals (mammalophilic). Most avian feeders exhibited marked habitat and stratification preferences. Differences in the number of flies attracted to various sizes of simultaneously exposed birds were significant at the 5% level. Except for the ornithophilic species occurring in woodland habitats, preferences for mammals and birds were (within the habitats studied) generally related more closely to host size than to any other apparent factor. Engorgement rates were closely related to the attractiveness of the hosts. Simulium meridionale Riley and Eusimulium aureum (Fries) were vectors of Leucocytozoon parasites to turkeys, as was S. rugglesi N. & M. to ducks. Prosimulium magnum D. & S., S. decorum Walk., S. luggeri N. & M., S. jenningsi Mall., S. venustum Say, and S. vittatum Zett. were occasional livestock pests.