AGE STRUCTURE, BLOOD-FEEDING BEHAVIOR, AND LEISHMANIA-CHAGASI INFECTION IN LUTZOMYIA-LONGIPALPIS (DIPTERA, PSYCHODIDAE) AT AN ENDEMIC FOCUSOF VISCERAL LEISHMANIASIS IN COLOMBIA

Ecological studies on the sand fly Lutzomyia longipalpis (Lutz & Neiva ) were conducted during 1990-1992 in a small rural community in Colomb ia where American visceral leishmaniasis (AVL) is endemic. Subsamples of sand flies collected weekly from pigpens, the interior of houses, a nd natural outdoor resting sites were dissected to determine physiolog ical age and Leishmania chagasi Cunha & Chagas infection rates. Eleven female L. longipalpis had flagellates in their gut, 2 of which were s uccessfully cultured and identified as Leishmania chagasi. The reprodu ctive status, stage of ovarian development, and trophic history of fem ale sand flies varied among sites, habitats, and time of collection. T ire percentage of parous females ranged from about one-third to two-th irds overall and varied seasonally. Of most relevance to AVL transmiss ion was the finding that 8% of L. longipalpis females were multiparous . In addition, our data suggest that L. longipalpis rest inside houses after blood-feeding outdoors, and that this species can blood-feed mo re than once during a single gonotrophic cycle.