To better understand the dispersion strategies of Triatoma infestans (Klug) (Hemiptera: Reduviidae, Triatominae), we evaluated the spatial effect of infested peridomicile and density vegetation cover in a historically endemic area for Chagas disease. The study was conducted in rural houses of the northwest of Córdoba province, Argentine, during 2012-2013. Active search of triatomines were made in domicile and peridomicile habitats. To characterize vegetation coverage, a thematic map was obtained considering five types of vegetation cover (closed/open forest, closed/open shrubland and cultural land). From each house we extracted the area of vegetation coverage, housing density and infested peridomiciles density. We used generalized linear models to evaluate the effect of these variables on the occurrence of infested peridomicile. According to our results, the probability of a peridomicile to be infested increases by 1.34 (95%CI [0.98; 1.90]) times more when peridomicile structures are in environments with higher housing density and by 1.25 (95%CI [0.84; 1.88]) more times when houses are surrounded by open shrublands. Among the multiple ecological determinants of peridomestic infestation, the influence of vegetation cover has been poorly studied. In this study we discussed the effect of the vegetation as a potential modulator of the dispersion strategies of T. infestans.

Understanding the dispersal capacity of Triatoma infestans, the main vector of Chagas disease in South America, is vital for vector control and managing recolonization after insecticide use. This study compares the seasonal frequency of melanic and non-melanic T. infestans morphs in Northwestern Córdoba Province, Argentina, and examines their association with environmental variables, morphometric traits, nutritional status, and flight capacity. Insects were collected at the beginning and end of the warm season. Dorsal coloration, morphometric traits, nutritional status, flight-related indices, climatic variables, and vegetation cover were recorded. Chromatic morph frequencies were analyzed using chi-square tests. Biological predictors were identified through multi-model inference, and environmental associations explored with Canonical Correspondence Analysis. Melanic individuals decreased from early to late warm season, especially males. Wing loading correlated strongly with morphotype, being higher in non-melanic forms. Pronotum size were also a significant predictor. Nutritional status had no clear effect. Cattle pasture cover and rainfall influenced morph frequency, mainly in males. These results reveal a complex interaction between phenotypic and environmental factors shaping color morph variation, highlighting the importance of understanding these dynamics to optimize vector surveillance and control in areas prone to reinfestation.

Triatoma infestans and Triatoma platensis are closely related species that may coexist in peridomestic habitats and produce viable hybrids. Since dispersal is a key process in the epidemiology of Chagas disease, understanding how hybridization affects flight-related traits is important. Here, we compared head and wing morphology of parental species and experimental hybrids to assess whether hybridization alters traits associated with flight capacity and dispersal potential. Hybrids were obtained by crossing T. infestans females with T. platensis males. Head and wing shape were analyzed using landmark-based geometric morphometrics, whereas size variation, allometric relationships, and wing aspect ratio were evaluated using generalized linear and generalized least-squares models. Significant differences in head and wing morphology were detected among parental species and hybrids. Overall, hybrids exhibited intermediate phenotypes, combining morphological features of both parental species. However, several flight-related traits, including wing shape and aspect ratio, were more similar to those of T. infestans than to T. platensis. The positive association between wing shape and aspect ratio indicated that hybrids possess relatively elongated and pointed wings, suggesting a dispersal potential closer to that of T. infestans. Overall, hybridization generated a distinctive combination of morphological traits with potential implications for vector dispersal and Chagas disease transmission.