Host-feeding behavior of mosquitoes (Diptera: Culicidae) in North Dakota, 2003 to 2006.

Mosquitoes are abundant near temporary, semipermanent, and permanent water in North Dakota and are associated with human and veterinary diseases. Little is known about the feeding habits of mosquitoes as related to the transmission of arboviruses. We report on the identification of vertebrate hosts of 9 species of mosquitoes collected in 2003 to 2006. Blood meals of 1,223 from 9 mosquito species were identified to vertebrate species by PCR assays using the mitochondrial cytochrome b gene. Aedes dorsalis (Diptera: Culicidae) and Culiseta inornata fed only on mammals, and Aedes vexans fed almost exclusively on mammals. Aedes trivittatus fed significantly more on mammals than on birds. Culex tarsalis acquired blood meals from the most diverse group of vertebrates, frequently fed on American Robins, and did not exhibit a seasonal shift of feeding on birds to mammals. The extensive feeding of Cx. tarsalis on passerine birds and the isolation of West Nile virus (WNV) from 2 specimens that had fed on passerines supports their role in horizontal transmission of WNV. This species also transmits western equine encephalitis virus. Host feeding by Ae. trivittatus, Ae. vexans, Cs. inornata, and Ae. dorsalis in relation to their possible importance in transmission of trivittatus virus, Cache Valley virus, Jamestown Canyon virus, Potosi virus, or snowshoe hare virus is presented. The identification of host feeding behavior pattern of specific species of mosquitoes enhances our understanding of the enzootic and epizootic nature of 7 viruses in North Dakota.