Uncovering host diversity and global distribution of Forcipomyia Meigen (Diptera: Ceratopogonidae) ectoparasitism on Lepidoptera larvae using citizen science records.

Parasitic interactions play a central role in shaping insect diversity; however, many host-parasite associations remain poorly documented, particularly among Diptera. Species of Forcipomyia (Microhelea) are known ectoparasites of other insects, yet information on their host associations is still fragmentary. The Fuliginosa species-group is known to be ectoparasite of larvae of Lepidoptera and Hymenoptera. In this study, we present the first global synthesis of ectoparasitism by Forcipomyia (Microhelea), Fuliginosa species-group, on caterpillars, integrating literature records with data obtained from the citizen science platform iNaturalist. A total of 109 validated photographic records from 29 countries were compiled, revealing 49 Lepidoptera species belonging to 14 families. When combined with literature records, 15 Lepidoptera families are recognized as hosts, including six reported here for the first time. This interaction shows a broader geographic distribution and higher host diversity than previously recognized, with first records from 17 countries. Our results highlight the potential of citizen science to reveal ecological interactions and demonstrate that parasitism by Forcipomyia on Lepidoptera larvae is more frequent, diverse, and widespread than previously documented.