The cuticular hydrocarbon pattern as a taxonomic tool for studying Triatoma dimidiata population structure

CALDERÓN FERNÁNDEZ G; JUÁREZ MP; MIJAILOVSKY S

Misiones, Argentina

Congreso; XL Reunión Anual de la Sociedad Argentina de Investigaciones Bioquímicas; 2004

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

The cuticular hydrocarbon fingerprint of T. dimidiata, a relevant Chagas disease vector in northern Latin America, was used to compare insect populations from different states from Mexico and Guatemala. The hydrocarbon composition was analyzed by capillary gas chromatography (CGC), structure identification was performed by CGC coupled to mass spectrometry (MS). The relative abundance of the hydrocarbon components was analyzed by principal component analysis and discriminant analysis. Hydrocarbon profiles showed lineal and methyl-branched chains between 21 to more than 40 carbon atoms, the prevailing structures were odd-numbered chains of 25 to 33 carbons. Quantitative rather than qualitative intraspecific differences were detected. Discriminant analysis results in 93.2 % of specimens correctly classified according to their collection sites and 78.4 % after reclassification by cross-validation. Four groups were easily distinguished, in coincidence to geographic vicinity; one included insects from Hidalgo, Veracruz, Chiapas and east Oaxaca states; a second group included Santa Rosa, Jutiapa and west Oaxaca, a third one corresponded to Cozumel, Yucatan and the nearby Peten jungle. A fourth group from Guatemala (Lanquin caves) was significantly different, posing concern on its taxonomic status.