| Summary: | Automatic-collecting, animal-baited traps were used to investigate the vertical activities and host preferences of Culicoides species in a forest in Giles County, Virginia. Using ropes and pulleys, rabbit and turkey-baited traps were positioned at ground level, 25, and 50 feet elevation in a forest tree so as to give Culicoides choices of avian or mammalian hosts at each vertical level. Culicoides species generally exhibited preferences for one or more of the vertical levels. The size of the host and its presence within the normal vertical activity area of the Culicoides were found to be more important than whether the host was a bird or a mammal. Three trapping methods (Goat-Baited Trap, Black Light Trap, and D-Vac) were employed simultaneously to investigate the seasonal and daily activity patterns of Culicoides and to determine the relative effectiveness of the three methods. The Black Light Trap was the most effective method for most of the species. The Goat-Baited Trap was selective for Culicoides species and was most effective for collecting Q. sanguisuga, the most abundant species. The D-Vac collected more species than the other methods, but several species were represented by only a few specimens. Two species (C. alexanderi and C. jamnbacki) were collected for the first time in Virginia, and 8 more were new records for Giles County. Graphs were presented showing seasonal distributions for 11 species, and preliminary indications were given for 8 more. Most species were crepuscular in their activities, with the greatest activity usually occurring in the evenings. Some species were nearly as active in the mornings as in the evenings, and one species, C. guttipennis, was most active during the nights and in the mornings. Culicoides sanguisuga exhibited 2 nearly equal activity peaks during the i-hour time intervals after sunset and before sunrise. Light intensities were nearly identical during those times and were more closely related to activity than were temperature or relative humidity. === Ph. D.
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