Eco-geographical differentiation among Colombian populations of the Chagas disease vector Triatoma dimidiata (Hemiptera: Reduviidae)

- We analyzed COI gene and microsatellites of several populations of T. dimidiata.
- Three groups associated with their eco-geographical distribution were identified.
- Inter-population structure weakly correlates with an isolation by distance model.

Triatoma dimidiata is currently the main vector of Chagas disease in Mexico, most Central American countries and several zones of Ecuador and Colombia. Although this species has been the subject of several recent phylogeographic studies, the relationship among different populations within the species remains unclear. To elucidate the population genetic structure of T. dimidiata in Colombia, we analyzed individuals from distinct geographical locations using the cytochrome c oxidase subunit 1 gene and 7 microsatellite loci. A clear genetic differentiation was observed among specimens from three Colombian eco-geographical regions: Inter Andean Valleys, Caribbean Plains and Sierra Nevada de Santa Marta mountain (SNSM). Additionally, evidence of genetic subdivision was found within the Caribbean Plains region as well as moderate gene flow between the populations from the Caribbean Plains and SNSM regions. The genetic differentiation found among Colombian populations correlates, albeit weakly, with an isolation-by-distance model (IBD). The genetic heterogeneity among Colombian populations correlates with the eco-epidemiological and morphological traits observed in this species across regions within the country. Such genetic and epidemiological diversity should be taken into consideration for the development of vector control strategies and entomological surveillance.

Bayesian cluster analysis of twelve T. dimidiata communities from three eco-geographical regions of Colombia. Bayesian arrays of individuals from each community assigned to each one of the four genetic clusters (grey scale). Each bar represents an individual was assigned to each cluster. Eco-geographical region names of communities are shown in bottom of figure.