Flight and nutritional status of sylvatic Triatoma sordida and Triatoma guasayana

Nutritional status relating to flight activity was investigated in natural populations of Triatoma sordida and T. guasayana during the dry season in t he Bolivian Chaco. The peak flight activity of both species was unimodal an d covered the period 61-180 min after sunset. The weight of insects was use d as the indicator of nutritional status. Interspecies comparisons employin g the same sex and type of capture showed a higher weight for T. guasayana. No significant difference according to weight was observed between flying insects and those collected in natural ecotopes (hollow nees and bromeliads ). More than 87% of insects collected from natural ecotopes displayed fligh t ability under the study conditions, explaining their tendency to invade a rtificial structures during the dry season.