ABSTRACT: Aleiodes Wesmael is the most diverse rogadine genus worldwide, with specialized koinobiont endoparasitic development in Lepidoptera caterpillars resulting in mummification of the host remains. This paper focuses on describing new Aleiodes species from the Yanayacu Biological Station, with special interest in those with biological information. We describe 24 new species (Aleiodes albidactyl sp. n., Aleiodes albigena sp. n., Aleiodes albiviria sp. n., Aleiodes bimaculatus sp. n., Aleiodes cacuangoi sp. n., Aleiodes colberti sp. n., Aleiodes delicatus sp. n., Aleiodes dyeri sp. n., Aleiodes elleni sp. n., Aleiodes falloni sp. n., Aleiodes frosti sp. n., Aleiodes kingmani sp. n., Aleiodes longikeros sp. n., Aleiodes luteosicarius sp. n., Aleiodes marilynae sp. n., Aleiodes mirandae sp. n., Aleiodes napo sp. n., Aleiodes nubicola sp. n., Aleiodes onyx sp. n., Aleiodes shakirae sp. n., Aleiodes stewarti sp. n., Aleiodes townsendi sp. n., Aleiodes tzantza sp. n., and Aleiodes yanayacu sp. n.) from Napo Province in Ecuador, 16 of which were reared from host caterpillars. With these results 89 species of Neotropical Aleiodes are now known, with 41 of them having host records. The most commonly reared species were in the circumscriptus/gastritor species-group, and mostly associated with Geometridae hosts (six of ten species). Three species of seriatus species-group, in contrast, were each reared from a different family. One of these species (i.e. A. frosti sp. n.), reared from Notodontidae, cuts a posterior radial opening in the mummy for emergence, a unique behavior in Aleiodes, recorded here for the first time. A. luteosicarius sp. n. is the first described species from Ecuador in the pallidator species-group. Differing from previously described pallidator species, which attack only Lymantriinae larvae, A. luteosicarius sp. n. attacks several species of Arctiinae larvae, being both subfamilies within Erebidae with densely setose caterpillars. We also describe new species of the gressitti and pulchripes species-groups.
