Host selection patterns of some Pakistan mosquitoes.

The host selection patterns of 18 species of Pakistan mosquitoes are described, emphasizing the presumed malaria vectors, Anopheles culicifacies, An. fluviatilis, and An. stephensi, and the probable vectors of West Nile virus, Culex pipiens fatigans and Cx. tritaeniorhynchus. All species tested, with the exception of Cx, p. fatigans, were considered to be essentially zoophilic. Few human feeds were recorded for An. annularis (0.7%), An. culicifacies (0.5%), An. fluviatilis (1.1%), An. nigerrimus (14.3%), and Cx. bitaeniorhynchus (2.8%), while Cx. p. fatigans (37.6%) commonly fed on man. No human positive feeds were recorded for An. stephensi. Temporal or spatial changes in host selection patterns were not discerned with the exception of Cx. p. fatigans, whose feeding patterns varied opportunistically with host availability. Cx. p. fatigans females collected from houses fed more commonly on man than those resting in cattle sheds or in agricultural fields. Cx. p. fatigans resting in cattle sheds during winter fed mostly on birds and bovids, changing to man and bovids during the spring and then to man and birds during summer. The relationships between these results and vector-borne disease transmission in Pakistan are discussed.