Cache Valley virus: isolations from mosquitoes in Saskatchewan, 1972-1974.

Eighteen isolations of Cache Valley virus (Bunyaviridae) were obtained from a total of 113,694 mosquitoes collected in Saskatchewan during the summers of 1972 to 1974. Most of the isolations were from mosquitoes collected during August. Culiseta inornata, the most abundant mosquito (38% of total collected), had the highest minimum vector-infection rate (0.

Intranasal exposure of the Richardson's ground squirrel to Western equine encephalomyelitis virus.

Adult Richardson's ground squirrels were infected with western equine encephalomyelitis virus by intranasal instillation. Mortality followed the instillation of a minimum threshold of 4.7 logs of virus while infection was produced by a dosage of 2.

Subcutaneous exposure of the Richardson's ground squirrel (Spermophilus richardsonii Sabine) to western equine encephalomyelitis virus.

Both adult and suckling Richardson's ground squirrels (Spermophilus richardsonii) were susceptible to subcutaneous exposure with western equine encephalomyelitis (WEE) virus, but the virus was more virulent for sucklings than adults. In sucklings, the incubation period was from 4 to 5 days, followed by apparent signs of central nervous system (CNS) involvement. Death occurred 10 to 13 days postexposure.

Laboratory studies on the transmission of western equine encephalitis virus by Saskatchewan mosquitoes. I. Culex tarsalis.

A Saskatchewan strain of the mosquito Culex tarsalis, transmitted a local strain of western equine encephalitis virus from chick to chick, between four and 44 days after an infective blood meal. At incubation temperatures of 69 and 75 degrees F, 120 transmissions occurred out of a possible 141, and all but seven of these were by single infected mosquitoes. At 75 degrees F virus titers in individual mosquitoes were more uniform and transmission was more efficient, than at 69 degrees F, although infection rates were similar at both temperatures.

The selection of juvenile entrants to mining.

McLintock, J. S. (1971).

Western equine encephalitis virus in Saskatchewan garter snakes and leopard frogs.

Western equine encephalitis virus was isolated from two naturally infected snakes on first bleeding and from seven others at subsequent bleedings, both with and without preliminary chilling. One snake, with neither detectable virus nor serum neutralizing antibodies when first bled, developed viremia later. Viremia in garter snakes has a cyclic rhythm independent of the temperature of the environment.