Phylogenetic analysis of morphometric and biological characters indicated that there are two distinct forms of Lutzomyia whitmani in Brazil: one is present both north and south of the River Amazonas in the State of Pará while the other occurs in northeast Brazil, in the State of Ceará, and further south, including the type locality in State of Bahia. The Amazonian form is reportedly neither strongly anthropophilic nor synanthropic, and it is the vector of Leishmania shawi; whereas the southern form is often collected peridomestically, while biting man, and has been found infected with Le.(V.) braziliensis. The ratio of the length of the genital filaments to that the genital pump was found to be consistently smaller in males of the Amazonian populations. A middle repetitive DNA element was isolated by differentially screening a genomic library made using Amazonian material, and the sequence was diagnostic for this form of Lu. whitmani (being absent or occurring in low copy number in the southern form). The total evidence suggests there are at least two, geographically-isolated forms of Lu. whitmani, which may represent different cryptic species.

O subgênero Trichopygomyia Barretto, 1962 do flebótomo Lutzomyia spp. França, 1924 é revisto e corresponde às espécies incomuns do grupo longispina de Theodor (1965). É também descrita Lutzomyia (Trichopygomyia) ratcliffei n.sp. da Bacia Amazônica. Figuras, chaves, mapas de distribuição e notas sobre ecologia são apresentados para todas as formas conhecidas. As espécies mais conhecidas são freqüentemente encontradas em todas de tatu e, portanto, podem ser vetores de Leishmania.

The subgenus Trichopygomyia Barreto, 1962 of the phlebotomine genus Lutzomyia França, 1924 is reviewed. This subgenus corresponds to the informal species group longispina of Theodor (1965). Lutzomyia (Trichopygomya) ratcliffei n.sp. from the Brazilian Amazon Basin is described. Figures, keys, distribution maps and notes on ecology are presented for all the known forms. The better known species are most frequently encountered in armadillo burrows and, therefore, could well be vectors of Leishmania.

Os machos de Lu. longipalpis ocorrem em duas formas distintas: uma com um simples par de manchas claras no 4º tergito e a outra com um par adicional de manchas caracterizadas no 3º tergito. Cruzamento entre linhagens obtidas no laboratório das duas formas, originárias de áreas alopátricas e simpátricas no Brasil, demonstrou que quase todos os machos falharam em inseminar fêmeas heterólogas. Observou-se também falhas na inseminação entre populações alopátricas de Lu. longipalpis com as mesmas características de manchas indicando a existência de duas ou masi formas num aparente complexo de espécies. A possibilidade de Lu. longipalpis sensu latu representar mais que um simples taxon é discutida e a relevância destes encontros no futuros estudos epidemiológicos do kala-azar é considerada.

The males of the sandfly Lutzomyia longipalpis occur in two forms, one which bears a single pair of pale spots on tergite 4 and another in which an additional pair of spots characterizes tergite 3. In crosses between laboratory reared stocks of the two forms originating from allopatric and sympatric sites in Brazil nearly all males of one form fail to inseminate females of the other. In addition, insemination failure between some allopatric populaytions of Lu. longipalpis with similar tergal spot patterns is recorded, indicating the existence of additional forms in an apparent species complex. The possibility that Lu. longipalpis sensu latu represents more than a single taxon is discussed and the relevance of these findings to future epidemiological studies on kala-azar is considered.