Ecogenetics of Triatoma sordida and Triatoma guasayana (Hemiptera : Reduviidae) in the Bolivian Chaco

Triatoma guasayana and two putative cryptic species pertaining to T. sordid a complex (named groups 1 and 2) occur in sympatry in the Bolivian Chaco. U sing multilocus enzyme electrophoresis and subsequent genetic analysis, our work assesses their population distribution and dispersal capacity in dome stic, peridomestic, and silvatic environments. Our collections by light tra p in the silvatic environment indicated a predominance of T. guasayana and T. sordida group 2 and a lesser abundance of T. sordida group 1 (less than or equal to 10% of the total captures). Their similar distribution in two s ilvatic areas 80 km apart supports the hypothesis of their homogeneous disp ersal through the Bolivian Chaco. The distribution of T. guasayana and T. s ordida groups 1 and 2 was similar between silvatic environment and peridome stic ecotopes where 25% of positive places was occupied by two or three spe cies. Bromeliads were confirmed as favorable shelter for T. guasayana but w ere free of T. sordida. T. sordida group 2. The spatial partition in the th ree species sampled in two distant sites suggested a reduced dispersive cap acity.