Predição da distribuição potencial da espécie introduzida Chrysomya albiceps (Diptera: Calliphoridae) na América do Sul

Abstract

Chrysomya (Robineau-Desvoidy, 1830) is a genus of Diptera that includes the "blowflies," dipterans associated with the transmission of infectious agents, causes secondary myiasis, and they have medical-veterinary importance due to affect the human and animal health. Among the species of this genus, Chrysomya albiceps (Wiedemann, 1819) is an exotic and invasive species present in South America, recorded for the first time in Brazil in the late 1970s. This species quickly spread across almost part of the continent, with confirmed records in 12 south American countries. The aim of the present study was to analyze, through ecological niche modeling, the potential areas of South America susceptible to the invasion of C. albiceps, as well as to identify the main environmental predictors that help explain the presence of the species in the subcontinent. Initially, 25 climatic, pedological, and anthropogenic variables were considered, both the native area (Africa) and the study area. Occurrence records were obtained from different databases, resulting in a total of 1,013 unique records with geographic coordinates. The candidate models (for the native area) were generated during the calibration process using the Maxent algorithm, and two final models were selected that met the selection criteria and presented very good AUC values and two final models were considered based on AUC values (0.878 and 0.930). The variable of potential evapotranspiration (PET) was the main contributor in the models, followed by the population density variable. Both variables together contributed to more than 60% of the model explanation for each model. The projection of the final models in South America showed areas of higher suitability in Argentina and almost coastal areas of the continent (mainly Brazil). Since C. albiceps is considered as a species highly tolerant to temperature, humidity, and elevation ranges, the results showed suitability areas with different types of climates and altitudes ranges. On the other hand, the mobility-oriented parity analysis (MOP) showed an extrapolation risk in the large area in Southern South America as suitable for C. albiceps, the species' adaptability and rapid evolutionary cycle suggest that it may still proliferate in these regions, despite the conditions not being entirely equivalent to its native range. The results align with the distribution of C. albiceps and indicate that the species may have adapted to the biotic and abiotic conditions of the new continent, demonstrating its ecological plasticity. However, they highlight the need for further research on biotic interactions, the impacts of its presence in different regions and on public health.