Viability and spatial structuring in a Triatoma maculata (Hemiptera: Reduviidae) laboratory colony fed with human blood

Immature and adult forms of Triatoma maculata have been captured repeatedly in and around the homes in the town of Xaguas, Venezuela. Because of its potential as a Chagas disease vector, a study was undertaken to evaluate the effect of human blood feeding on the viability and spatial structuring of a laboratory colony of this species. The effect of human blood feeding was determined for the viability of a T. maculata laboratory colony, as well as its spatial structuring. Insects were fed with human blood on artificial feeder. Spatial structuring was undertaken by the generalized analysis of by geometric morphometry. The average fecundity of 27.7 eggs/female/lifetime was found, with a mean time to oviposition of 32.7 days, and a female longevity of 39.2 days. The longest inter-molt period was at the fifth nymphal stage (45.9 days), whereas the shortest was at 18.4 days, during the first nymphal stage. The highest mortality of nymphs was observed at the fifth nymphal stage (77.8%). The lowest molting percentage was observed in the fifth nymphal stage (22.2%). No differences in the size of wings and heads were detectable; although differences in the head shape of individuals of the same sex from different environments were noted. Wing-shape differences were found only between the males of peridomestic and domestic ecotopes. Triatoma maculata may be entering human dwellings to feed on non-human animals, or alternatively, may be in an incipient state of adaptation to a domestic ecotope for feeding on human beings.