FLAGELLATE INFECTIONS IN CAVE-DWELLING SANDFLIES (DIPTERA, PSYCHODIDAE) IN BELIZE, CENTRAL-AMERICA

Nearly 2000 phlebotomine sandflies collected in caves in Belize were examined for flagellate infections in the gut. Infections were found in 4% of Lutzomyia trinidadensis (Newst.) and in 42% of L. beltrani (Belize form). The 2 spp. of sandflies were infected with different species of parasites. The sources of infections in L. trinidadensis were not established, but females probably became infected when taking blood-meals on a vertebrate. One specimen of L. trinidadensis infected with flagellates was infected with filaria worms. Circumstantial evidence suggests that L. beltrani is the insect host of Trypanosoma leonidasdeanei, a blood parasite of insectivorous bats. The physiological condition of infected and uninfected L. beltrani, distribution of flagellates in the gut, and differences in the incidence of infections, are described. The presence of the parasites in the gut disturbs some physiological processes in the fly; the presumed Chiroptera/T. leonidasdeanei/L. beltrani association may be a recent evolutionary development. A model of population structure for a community of New World Phlebotominae, derived from observations on L. beltrani, is presented.