Distribution and Primate Hosts of the Bot Fly <i>Cuterebra baeri</i> Across the Americas

Species distributions are influenced by evolutionary history and interactions with biotic and abiotic factors, thereby providing crucial insights into ecological interactions. However, despite their ecological significance, parasite distribution maps remain scarce. This study investigated the distribution of Cuterebra baeri, a primate-specific ectoparasite, through comprehensive systematic literature review and analysis of data from iNaturalist. Cuterebra baeri was documented in primates ranging from southern Mexico to southern Brazil, including the initial documentation from Guatemala. Four previously undocumented howler monkey host species were identified (Alouatta discolor, A. guariba, A. nigerrima, and A. sara), expanding the Alouatta host species count to nine. Alouatta palliata exhibited the highest proportion of photographic observations from iNaturalist depicting at least one individual with nodules. Spatial analysis revealed 10 clusters in the distribution of C. baeri, primarily concentrated north of the Equator around 10° N. These findings carry significant implications for primate conservation and behavioral ecology, as sites with parasitized monkeys facilitate the identification of populations experiencing health risks and likely support populations employing behavioral strategies to mitigate parasitic metabolic costs. This study demonstrates how citizen science data can effectively complement traditional scientific studies to generate comprehensive distributions of primate parasites.