A Winter Isolation of Western Equine Encephalitis Virus from Hibernating Culex tarsalis Coquillett

Abstract
A total of 1361 hibernating female C. tarsalis mosquitoes, comprising 31 pools, was collected in mines in Colorado foothills from Dec. 15, 1953, to Feb. 9, 1954. One of these pools, collected Dec. 30, 1953, contained WEE virus upon inoculation into freshly hatched chicks. The finding of such large numbers of hibernating C. tarsalis and the recovery of WEE virus from them, may contribute to the knowledge of the overwintering mechanism of this virus.