Parasitoidism efficiency of two species of Chalcididae (Insecta: Hymenoptera) attacking Lepidoptera in urban areas of Brazil

Chalcididae are parasitoid wasps with potential for use in biological control due to their association with arthropod hosts of economic and medical importance. Few studies have assessed their effectiveness or natural parasitoidism rates. This study aimed to expand knowledge on Chalcididae by evaluating their parasitoidism on two Lepidoptera species in urban areas of Vitória, ES, Brazil. In 2019 and 2024, we sampled 24 and 39 pupae of Dione vanillae (Linnaeus) (Nymphalidae) on Passiflora edulis Sims (Passifloraceae), respectively. In 2023, we collected 74 pupae of Melete lycimnia flippantha (Fabricius) (Pieridae) that were feeding on Tripodanthus aff. acutifolius (Loranthaceae), which was parasitizing Samanea inopinata (Harms) Barneby and J.W. Grimes (Fabaceae). High parasitoidism rates were recorded for both hosts. From Do. vanillae, an undescribed gregarious Conura (pygmaea group) (Chalcididae) was responsible for 70.8% (2019) and 100% (2024) parasitoidism rate, and Brachymeria annulata (Fabricius) (Chalcididae) emerged from 16.6% of pupae — representing the first record for this host. Brachymeria mnestor (Walker) was responsible for a 45.9% parasitoidism rate on M. lycimnia flippantha, also a first record for this host association. These findings reinforce the potential of Chalcididae as effective natural enemies of crop pests, with average parasitoidism rates often above 40%. Gregarious and host-specific species may be especially effective in biological control strategies.