Abstract

Cytogenetic analysis of Triatoma pseudomaculata Corr�ªa and Esp�­nola, 1964 (Hemiptera, Triatominae) from different Brazilian states

Author(s): C.H.L. Imperador, K.C.C. Alevi, J. Oliveira, J.A. Rosa and M.T.V. Azeredo-Oliveira

Triatoma maculata and T. pseudomaculata are allopatric; however, it is believed that T. maculata was introduced into the Brazilian northeast by passive transportation of the nymphs between the feathers of migratory birds, followed by the speciation of T. pseudomaculata. T. pseudomaculata is the second most epidemiologically important species in the northeast of Brazil after T. brasiliensis. Therefore, given the broad range of T. pseudomaculata, the objective of the present study was to cytogenetically analyze different populations of T. pseudomaculata from different Brazilian states in order to investigate possible intraspecific chromosomal variation between them. Three adult T. pseudomaculata males from each population (Pernambuco, Ceará, Paraíba, Bahia, Rio Grande do Norte, and Piauí) were analyzed by lacto-acetic orcein and C-banding. All ofthe specimens analyzed exhibited the same cytogenetic characteristics, i.e., 22 chromosomes (20 autosomes and XY), a chromocenter formed by the X and Y sex chromosomes and one pair of autosomes, and heterochromatin blocks in three or four pairs of autosomes. These data confirm that all of the populations analyzed were T. pseudomaculata, and although they may be subject to different selection pressures they have maintained the genetic integrity that characterizes the species.

• PDF