Behavioral plasticity of Triatominae related to habitat selection in northeast Brazil.

Triatoma pseudomaculata Corrêa and Espínola, 1964 and Triatoma juazeirensis Costa and Felix, 2007 ( = T. brasiliensis Neiva, 1911 [part]), are sylvatic vectors of Trypanosoma cruzi (Chagas, 1909), the causative agent of Chagas disease, in northeast Brazil-especially in the caatinga region. In an area of caatinga in the State of Bahia, we compared the wild and peridomestic habitats of these two species of Triatominae to assess their behavioral plasticity in relation to habitat selection in different environments. In the sylvatic environment, the habitat of these two species is never shared. T. pseudomaculata is found in trees and bird nests, but without apparent preference for any particular tree species. In contrast, T. juazeirensis is exclusively rupicolous (found among rocks). Both species invade peridomestic structures but do not display a significant ability to colonize human dwellings. In the peridomestic area, they are highly adaptable to different habitats and can occupy substrates that they do not colonize in the sylvatic environment. This behavioral plasticity seems to be more striking in T. juazeirensis-rupicolous in sylvatic environments but colonizing wooden structures in the peridomicile in >80% of cases.

Risk factors for reinvasion of human dwellings by sylvatic triatomines in northern Bahia State, Brazil

O objetivo deste estudo foi o de explorar (em Curaçá, município do Estado da Bahia, no Nordeste brasileiro) os possíveis fatores associados à infestação das moradias pelo Triatoma brasiliensis ou Triatoma pseudomaculata, dois triatomas das espécies silvestres. Usamos uma análise "logística" de múltipla regressão para mostrar como as características estruturais da área do peridomicílio associadas ao número de animais e a fatores sociológicos favorecem a infestação em algumas moradias. Isso sugere que T. brasilienses está associado às atividades humanas enquanto T. pseudomaculata está associado à vegetação e aos animais. Assim, o manejo da pecuária é um importante fator de risco para a infestação de triatomíneos.

Risk factors for reinvasion of human dwellings by sylvatic triatomines in northern Bahia State, Brazil.

The aim of this study in Curaça, Bahia, Northeast Brazil was to explore possible factors associated with the infestation of human dwellings by Triatoma brasiliensis or Triatoma pseudomaculata, two sylvatic triatomine species. We use multiple logistic regression analysis to show how structural features of the peridomiciliary area combine with the number of animals and sociological factors to allow infestation of some dwellings. It is suggested that T. brasiliensis is associated with human activities, while T. pseudomaculata is associated with vegetation and animals. Peridomiciliary farm animals are a strong risk factor for triatomine infestation.