FIG. 1.

West Nile virus (WNV)-positive species composition in 4 locations from 2002 to 2008. (Upper panel) Number of positive pools, regardless of pool size. Cx. pipiens is the most abundant species in all locations, followed by Cx. restuans, except in Philadelphia. In Philadelphia, the second most abundant species is Cx. salinarius. (Lower panel) Number of total mosquitoes in positive pools. Cx. salinarius is the most abundant in Philadelphia, but not present in Pittsburgh at all, and has a low quantity in Harrisburg and Williamsport as well. This figure summarizes the species composition over entire 7-year period. We do not observe substantial species composition change among different years.