Behaviour of Lutzomyia longipalpis in an area of southern Honduras endemicfor visceral/atypical cutaneous leishmaniasis

The predominant sandfly in Las Maria de Pavana, Choluteca, Honduras, was fo und to be Lutzomyia longipalpis, most (69%) of the 791 specimens of this sp ecies caught being male. When local Lu. longipalpis were studied over 1 yea r (1986-1987) using CDC traps, peaks in the size of the adult population we re observed in December and July, each after a period of rain. Most [51% (2 4/47)-67% (97/144)] of the flies caught inside houses were female whereas m ost [55% (6/11)-56% (37/66)] of those caught outside were male. Far more Lu . longipalpis of both sexes were collected, per h of collection from cattle and horses than from dogs or pigs, the vast majority (83%-93%) of the flie s caught on each type of animal being male. The males may benefit from rest ing on the mammals because the females with which they mate come to the sam e animals for blood. The females may benefit by the presence of the males, not only by the increased chance of finding a mate but also because pheremo nes from the males may attract the females both to the males and to a blood meal source. The adult Lu. longipalpis only appeared to be active during th e hours of darkness, none alighting in the twilight of dawn (04.00-06.00 ho urs) or dusk (18.00-20.00 hours) on the large mammals investigated.