American cutaneous leishmaniasis (ACL) in Brazil is caused by a variety of dermotropic Leishmania species and the greatest diversity of these parasites is to be found in the Amazon Region.Transmission of the causal agents involves different species of phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) in close relationship with the mammalian reservoir hosts of the parasites, with the consequent formation of a number of different transmission cycles throughout the country. The data from ecological and epidemiological studies on the different species of the subgenera Viannia and Leishmania, together with those from experimental laboratory transmissions, have either suggested or definitely indicated certain species of sand flies as being responsible for the transmission of ACL. Relatively few, however, have been considered as outstandingly important vectors.According to the taxonomic criteria proposed by Young and Duncan (1994), three genera of sand flies are recognized in the New World: Lutzomyia França & Parrot, 1924; Brumptomyia França &Parrot, 1921 and Warileya Hertig, 1940. The genus Psychodopygus Mangabeira, 1941 has been accepted by some (Fraiha et al. 1971, Fraiha & Ward 1974, Forattini 1973, Lainson et al. 1973 and modifications of the taxonomy have been suggested (Galati 2003). In this review, however, we propose to follow that of Young & Duncan (1994).
Vectorial competence of some neotropical sand fliesLutzomyia (Nyssomyia) intermedia (Lutz & Neiva, 1912) -L. intermedia, described from specimens collected in the Fazenda Ouro Fino, in the state of Minas Gerais (MG), where it was found to be abundant in houses, was one of the first species of sand fly to be described in the Neotropical Region.In the 1940's, important studies on the biology of L. intermedia s.l. were made by Barretto (1943) in the state of São Paulo (SP), together with observations on the behaviour of some other species of sand fly. It is a species found in both primary and secondary forests and particularly in areas where deforestation has gradually modified the ecological profile -clearly seen in those parts of the country that underwent past colonization. As long ago as 1943, Barretto suggested that L. intermedia s.l. had, in fact, developed a preference for secondary forest or low, bushy vegetation located in areas suffering from such human impact and according to Tolezano et al. (1980), the environmental changes that took place in SP at the beginning of the 20th century certainly modified the composition of the phlebotomine fauna. While this caused other species of silvatic sand fly to disappear, or survive at low frequency, L. intermedia s.l. adapted so well to the peridomestic habitat that it actually has become the predominate species of sand fly in a new epidemiological profile for ACL in this region. These authors further suggested that the small numbers of this sand fly now captured in the remaining forest indicates that transmission of ACL by L. intermedia is now taking place solely outside of that habitat.Like most s...