Chemical taxonomy of Triatoma dimidiata populations from Mexico and Guatemala: analysis of the cuticular hydrocarbon pattern

CALDERÓN FERNÁNDEZ G; JUÁREZ MP; SALAZAR SCHETTINO PM; RAMSEY J; MONROY MC

Valencia, España

Congreso; IX European Multicolloquium of Parasitology – IV Congreso de la Sociedad Española de Medicina Tropical y Salud Internacional; 2004

Sociedad Espanola de Medicina Tropical y Salud Internacional

The intraspecific variability of T. dimidiata Latreille (Reduviidae, Triatominae),  a major vector of Chagas disease, was studied in localities from seven states in Mexico and four departments in Guatemala. Insects were collected from domestic, peridomestic and sylvatic habitats. The cuticular hydrocarbon composition was analysed  by capillary gas chromatography, major components were straight chains from 25 to 33 carbons plus methyl-branched chains up to 41 total carbons. The hydrocarbon pattern was analysed using ordination and classification techniques. A significant discrimination was obtained according to their geographical location. Mexican insects were differentiated in three major regions corresponding to the Gulf Coast (Veracruz and Hidalgo), Yucatan peninsula, and the South Pacific Coast (Oaxaca, Chiapas) in Mexico. In Guatemala, northern (sylvatic) insects were differentiated from southern conspecifics (domestic).When both countries were analysed together, 80.9% of the insects were correctly classified, and differentiation according to location was maintained; insects from Peten were grouped with those from Yucatan according to their geographic vicinity. A very distinctive hydrocarbon pattern easily separated insects collected from caves in the north-central region of Guatemala from all other T. dimidiata insects, posing concern about their taxonomic status.