Effect of habitat fragmentation on rural house invasion by sylvatic triatomines: A multiple landscape-scale approach

Abstract

After the decrease of the relative importance of Triatoma infestans, a number of studies reported the occurrence of sylvatic triatomines dispersing actively to domestic environments in the dry western Chaco Region of Argentina. Anthropic modification of the landscape is mentioned as one of the main causes of the increase in domicile invasion. The aim of this study was to describe the occurrence and frequency of sylvatic triatomines invading rural houses, and to evaluate the effect of habitat fragmentation and other ecological factors on the invasion of rural houses in central Argentina. We hypothesized that the decrease in food sources and the loss of wild ecotopes, as a consequence of habitat fragmentation, increase the chances of invasion by triatomines. The entomological data was collected by community-based vector surveillance during fieldwork carried out between 2017–2020, over 131 houses located in fourteen rural communities in the northwest of Córdoba Province (central Argentina). We used generalized linear models to evaluate the effect of (i) the environmental anthropic disturbance in the study area, (ii) the composition and configuration of the landscape surrounding the house, (iii) the spatial arrangement of houses, (iv) and the availability of artificial refuges and domestic animals in the peridomicile, on house invasion by triatomines. We report the occurrence of seven species of triatomines invading rural houses in the study area -T. infestans, T. guasayana, T. garciabesi, T. platensis, T. delpontei, T. breyeri and P. guentheri-. Study data suggest that invasion by triatomines occurs with higher frequency in disturbed landscapes, with houses spatially isolated and in proximity to subdivided fragments of forest. The availability of domestic refuges in the peridomestic structures as well as the presence of a higher number of domestic animals increase the chances of invasion by triatomines.

Presence ofTriatoma breyeri(Reduviidae, Triatominae) in Bolivia

“…It predominantly inhabits the lower sections of branch fences, typically in proximity to the burrows of small rodents of the Caviidae and Cricetidae family [3]. It is reported that during the summer, adults can be encountered in the vicinity of houses and, occasionally, inside rooms [20–22]. However, it is important to note that they do not establish colonies within domestic environments [21, 23, 24].…”

Socio‐environmental factors associated with the occurrence of triatomines (Hemiptera: Reduviidae) in an endemic municipality in northern Minas Gerais, Brazil

“…Anthropogenic activities can cause depredation of vegetation, reduction of wild animals, and offer risks of transferring triatomines and trypanosomatids from the wild environment to the home environment (Fernandes et al, 1994; Figueiredo et al, 2007; Freitas et al, 2004). Studies such as Abad‐Franch et al (2010), Gottdenker et al (2011) and Cardozo et al (2021), demonstrate that anthropization influences the occurrence or invasion of triatomine species in households. While study by Leite et al (2011) suggests that preserved landscapes can contribute to the distribution of triatomines, due to the greater number of populations that inhabit these environments.…”

“…Subsequently, models were ranked according to the AICc values, as the lowest values suggest a better compromise between the adjustment and the complexity of the model. The value of the predictor variable coefficient and their 95% confidence interval (95% CI) were estimated by averaging the coefficient value in each model where the variable was present, weighted by the model contribution to the total variance (Cardozo et al, 2021).…”

“…The multi-model inference approach based on the Akaike Information Criterion (AICc) was used to estimate the effect of predictors and their relative importance over the response variables (Burnham & Anderson, 2002). Basically, we tested 44 models in where the variable was present, weighted by the model contribution to the total variance (Cardozo et al, 2021).…”

“…The adaptation of triatomines to the domestic environment and the circulation of T. cruzi between wild and domestic animals are factors that determine the establishment of human infection (Costa et al, 2011). Studies show that some environmental factors, such as the presence of vegetation (Cardozo et al, 2021), anthropic alterations (Abad-Franch et al, 2010;Gottdenker et al, 2011), as well as sociodemographic factors such as electricity (Castro et al, 2010;Erazo & Cordovez, 2016) and street lighting (Pacheco-Tucuch et al, 2012), may interfere with the occurrence of triatomines. However, to date, there has been no record of work that investigated these factors in the municipality of Montes Claros, in the state of Minas Gerais.…”