Phlebotomine sandflies were collected simultaneously at ground level, 25 ft and 40 ft in an area of medium bush in British Honduras (Belize).
Flies were captured on human bait, with rat-baited oil-traps and with miniature light-traps, and some resting individuals were collected at each level. One species of Brumptomyia França and 18 of Lutzomyia França & Parrot were obtained. Brief notes on some of these species are given.
Miniature light-traps provided the widest range of species, were the most satisfactory means for collecting Brumptomyia, L. steatopyga (Fairchild & Hertig) and L. carpenteri (Fairchild & Hertig), and yielded new information on the flight activities of L. deleoni (Fairchild & Hertig) and L. panamensis (Shannon).
Most species collected were found to be predominantly arboreal in habit, L. permira (Fairchild & Hertig) and Lutzomyia sp. P being almost exclusively so. Some species (L. panamensis, possibly L. geniculata (Mangabeira) and L. bispinosa (Fairchild & Hertig)) live amongst the foliage but descend to the forest floor to seek blood-meals. A few species (L. steatopyga, L. deleoni and L. olmeca (Vargas & Díaz Nájera)) are active mainly near the ground, though the occasional specimen may be carried much higher.
L. olmeca is the principal vector of rodent leishmaniasis in British Honduras. In the present study, no evidence was obtained to incriminate any other species of Phlebotomine as an insect host for Leishmania mexicana, and the mode of transmission of the parasite to man remains obscure.