Intraspecific Variability in <I>Triatoma dimidiata</I> (Hemiptera: Reduviidae) Populations from Guatemala Based on Chemical and Morphometric Analyses

Abstract

The intraspecific variability of Triatoma dimidiata Latreille, a major vector of Chagas disease, was studied in four departments of Guatemala. Insects were collected from either domestic and sylvatic habitats, and their cuticular hydrocarbon pattern and head morphology were analyzed using ordination and classification techniques. A significant discrimination was obtained both with morphometric and hydrocarbon analyses. Insects from northern departments were easily differentiated from southern conspecifics. Distinctive hydrocarbon pattern and head shape were detected for insects collected from caves in the north central region of the country, posing concern about their taxonomic status.

Assessment of Triatoma Dimidiata Dispersal in the Yucatan Peninsula of Mexico by Morphometry and Microsatellite Markers

“…These results are in good agreement with previous population genetic studies of T. dimidiata that showed a weak population structure over large distances. Previous morphometric analysis showed significant differences between populations from central Mexico and Guatemala, 13,15,25 and populations from the Peten region of North- * Bug assignment to the different biotopes was determined from probabilities calculated from the discriminant scores of a separate analysis of male and female bugs. The combined number of male and female bugs assigned to each biotope is presented for each collection site and in parenthesis as a percentage of bugs collected in each site.…”

“…Results are presented as canonical maps of the first and second canonical discriminant factors, and statistical significance of potential differences between populations was assessed by Wilks' Lambda. 13,25 Prob-abilities of bug assignment to distinct collection sites were also calculated from the discriminant scores to identify potential migrants from one population to another. Agreement between the assignments and the field collection sites was assessed by Kappa statistics.…”

“…Our previous work suggests that it is important to have a good understanding of T. dimidiata dispersal to design appropriate vector control strategies in the region. Recent studies on T. dimidata from different regions, using morphometry, chemical and random amplified polymorphic DNA (RAPD) molecular markers, [10][11][12][13][14][15] suggested only weak genetic structuring among populations and that this species has strong dispersal capabilities. However, although these techniques may be sufficient to detect clearly defined subpopulations separated by large distances (more than 120 km), they may have limited resolution to detect population structure over smaller distances and between biotopes.…”

Chromosomal variation and genome size support existence of cryptic species of Triatoma dimidiata with different epidemiological importance as Chagas disease vectors

“…It shows a higher Nei's genetic distance when compared to the other populations, which is not correlated with the geographic distance. The analysis of phenetic markers, such as head morphometry (Fernandez et al. 2005; Lehmann et al.…”