Two species of mosquitoes, Mansonia perturbans (Walker) and Psorophora ferox (Humboldt), were allowed to feed upon guinea pigs infected with the virus of Venezuelan equine encephalomyelitis. After 2 weeks incubation at 80[degree]F, the infection rate and guinea pig transmission rate for M. perturbans were found to be 83% and 38%, respectively, and for P. ferox, 84% and 11%, respectively. Virus was isolated from 7 of 16 M. perturbans egg rafts, but not from the eggs of P. ferox. The significance of the infected eggs is still unknown.