Figure 2. Dynamics of biting density and sporozoite positive salivary glands (including Plasmodium knowlesi) of Anopheles dirus mosquitoes in Khanh Phu forest, Vietnam. The solid red line connects the points of mean monthly An. dirus density (bites/person-night). Bars indicate the monthly number of sporozoite-positive salivary glands: white, P. knowlesi; gray, other species. The first mosquito found with P. knowlesi in August 2008 was described in Nakazawa et al. (11).