Abstract
The infection of A. aztecus and A. quadrimaculatus was obtained by permitting mosquitoes to bite on hamsters the 5th, 6th and 7th days after blood infection. Feedings after the 8th day were not infective. A. aztecus is the most susceptible and A. albimanus was refractory to P. berghei. Transmission was obtained by injecting hamsters and rats with macerated infected A. aztecus.