Parasitismo por Metacuterebra infulata (Diptera: Oestridae) em Hylaeamys megacephalus (Rodentia: Cricetidae) no Cerrado Brasileiro

Abstract

Parasitism is one of the ecological interactions shaping the structure of communities and population dynamics. The prevalence of infection is driven by environmental and intrinsic host attributes, leading to spatio-temporal dynamics of host-parasite infections. Larvae of Cuterebrinae flies are parasites that infect mammals, such as rodents, being observed in the Neotropical Hylaemys megacephalus within the Brazilian Cerrado. Therefore, in this study, we aimed to describe interaction between bot flies and the rodent H. megacephalus, identifying the parasite species infecting the studied rodent, the parasite prevalence, intensity and infection site. H. megacephalus. We tested whether the parasitism was higher during the wet season, and whether males were more frequently infected than females. The study was carried out between 2019 and 2023 at Fazenda do Glória, through trapping sessions. Botfly larvae were removed from H. megacephalus individuals, and raised in BODs until complete development of the adult flies for proper identification. Botflies infecting H. megacephalus were identified as Metacuterebra infulata, and this is the first report of a host for this parasite. Moreover, we report a new botfly species parasitizing H. megacephalus. Prevalence of M. infulata in the rodent population was 15.28% and most hosts (more than 90%) presented only one botfly at each time. Most larvae were found at the inguinal region, which may indicate host specifity, with greater incidence of infections among adults. Contrary to our hypothesis, botfly infection presented a multivoltine pattern, in which infections occurred along the entire year, irrespective of climatic season. However, we observed a slight peak in infections during April (transition from wet to dry season). It is possible that this peak may reflect the time interval between the botfly oviposition behavior, that is associated to the warm and wet conditions during the wet season, and the development of the L3 botfly larvae in the host. Finally, we also failed to find any difference in M. infulata prevalence between males and females. Such pattern may be associated to the lack of sexual dimorphism in H. megacephalus, leading to similar chances of parasite encounter between the sexes, and similar susceptibility of males and females due to the behavioral patterns of botfly oviposition and costs of reproduction for both sexes.