Indirect-host-finding
Guides
Trigonaloidea
Trigonaloidea is a monotypic superfamily of Hymenoptera containing the single family Trigonalidae, comprising approximately 90-110 cosmopolitan species. The superfamily is of uncertain phylogenetic placement within Apocrita, sometimes associated with Evanioidea but currently treated as distinct. Trigonalids exhibit highly unusual biology: eggs are laid on foliage and hatch only upon ingestion by sawfly or lepidopteran larvae, subsequently developing as hyperparasitoids of primary parasitoids within those hosts. The sole European species, Pseudogonalos hahnii, is the only representative recorded from Britain and Ireland, where it is rarely encountered and possibly declining.