Metaphase karyotypes and G-banding in sandflies of the Lutzomyia longipalpis complex.

Mitotic metaphase chromosomes (2n = 8) from brain cells of fourth instar sandfly larvae of four geographical strains of the Lutzomyia longipaplis complex were examined microscopically, with bright-field illumination, after staining by a new G-banding technique involving exposure of air-dried chromosome preparations to quinacrine and ultraviolet light. Differences of G-banding and/or position of the centromere on chromosome 4 (the smallest chromosome pair) distinguished four putative sibling species from Costa Rica, Colombia and Brazil (distinctive populations from Jacobina and Lapinha Caves). The karyotype of the population from Jacobina, Brazil, showed an apparently plesiomorphic pattern of G-banding. On the basis of their recognizably different mitotic karyotypes, cytogenetic identification of separate taxa in the L. longipalpis complex should be useful for specific female vector competence and ecology studies.