COUNTRYWIDE PREVALENCE OF ASCOGREGARINA-CULICIS (APICOMPLEXA, LECUDINIDAE), A PROTOZOAN PARASITE OF AEDES-AEGYPTI IN TRINIDAD, WEST-INDIES

The prevalence of the gregarine parasite Ascogregarina culicis was det ermined for Aedes aegypti populations in Trinidad, West Indies. Over 5 months, a total of 5,651 Ae. aegypti larvae were collected and identi fied from 419 sites throughout Trinidad as part of a national dengue s urveillance program. Ascogregarina culicis infections were detected in 13.4% of 1,986 Ae. aegypti larvae dissected. In 7 of 8 counties or ma jor subdivisions where this parasite was detected in Trinidad, the pre valence per locality ranged from 9.6 to 17.1% with an associated paras ite density of 19.1-51.9 trophozoites/larva. Confirming that Ae. aegyp ti populations in Trinidad are highly susceptible to infection with A. culicis parasites, experimental studies showed that a strain of A. cu licis from Florida readily infected 3 strains of Ae. aegypti from Trin idad with essentially no associated mortality. This report extends the known geographic range of A. culicis in Ae. aegypti populations and r epresents one of the first country-wide surveys for this gregarine par asite.