Range size positively correlates with temperature and precipitation niche breadths but not with dietary niche breadth in triatomine insects, vectors of Chagas disease.

Ecological theory predicts that species that can utilise a greater diversity of resources and, therefore, have wider niche breadths should also occupy larger geographic areas (the 'niche breadth-range size hypothesis'). Here, we tested this hypothesis for a blood-sucking group of insects of medical significance: the Triatominae (aka 'kissing bugs') (Hemiptera: Reduviidae). Given that niches can be viewed from different perspectives, we tested this hypothesis based on both dietary and climatic niches. We assembled the most complete dataset of triatomine feeding patterns to date by reviewing 143 studies from the literature up to 2021 and tested whether the niche breadth-range size hypothesis held for this group for both dietary and climatic components of the niche. Temperature and precipitation niche breadths were estimated from macro-environmental variables, while diet breadth was calculated based on literature data that used PCR and/or ELISA to identify different types of hosts as blood sources per triatomine species. Our results showed that temperature and precipitation niche breadths, but not dietary breadth, were positively correlated with range sizes, independent of evolutionary history among species. These findings support the predictions from the range size-niche breadth hypothesis concerning climate but not diet, in Triatominae. It also shows that support for the niche breadth-range size hypothesis is dependent upon the niche axis under consideration, which can explain the mixed support for this hypothesis in the ecological literature. Author summary: Many triatomine species carry the parasite Trypanosoma cruzi, a flagellate protozoan that causes Chagas disease in animals and humans, posing a long-standing public health threat to communities in the Global South. We investigated how the niche of triatominae species correlates with their geographic range. We compiled a comprehensive dataset on their feeding habits and environmental preferences and found that temperature and precipitation niche breadth correlated geographic range size but dietary breadths did not. These findings highlight the complexity of ecological relationships and contribute to a better understanding of how species interact with their environment, and can play a crucial role in determining the range of these vectors. Thus, this knowledge can aid in the development of more effective strategies for managing vector-borne diseases. [ABSTRACT FROM AUTHOR]