New insights into the biology of the rare ectoparasitoid rhopalosomatid wasps (Hymenoptera: Rhopalosomatidae) in the Neotropics: parasitoid–host relationships in Brazil and Costa Rica

Abstract Rhopalosomatidae (Hymenoptera, Vespoidea) are rare ectoparasitoid wasps that parasitize crickets (Grylloidea), with few records documented in the literature, which originate from the Nearctic and Australian regions. Here, we report the first record of Rhopalosomatidae larvae parasitizing crickets of the family Phalangopsidae in the Neotropics. Specimens of Ubiquepuella telytokous Fernandes, 2015 were collected in Minas Gerais (cave) and in Rio de Janeiro (tree trunks in Atlantic Forest fragments), Brazil, harbouring rhopalosomatid larvae. Parasitized specimens of Eidmanacris Chopard, 1956 were also observed in caves in Minas Gerais. This new host‐parasitoid association provides insights into the diversity and ecological interactions of these wasps in the Neotropics, where knowledge remains scarce. Additionally, we highlight the potential of citizen science platforms, such as iNaturalist, for expanding the documentation of parasitoid‐host relationships, as online records revealed other possible cases of parasitism in Brazil and Costa Rica. Our findings emphasise the need for further research on Rhopalosomatidae in the Neotropical region, particularly regarding their host specificity, life cycle and parasitoid–host relationships.