Abstract
More than 160TF mammals were examined for infections of Leishmania mexlcana. Fourteen infected rats belonging to 3 species were trapped. A 4th species was experimentally infected. More than 3000 female sandflies attracted to rats and opossums are recorded, principal species being Lutzomyla cruciataL. flaviscutellataL. panamensisL. shannon!, L. permira and L. trinldadensls. More than 2000 sandflies were dissected and flagellates found in 12. Three strains from L. flaviscutellata proved to be infections of L. mexicana. Many observations on the ecology of the rats and sandflies are presented and discussed. The rat Qtotylomys phyllotis is the principal reservoir host and the fly L. flaviscutellata is the principal vector of L. mexlcana in British Honduras.