Chalcid wasps (Hymenoptera: Chalcidoidea) associated with plant galls in India

Chalcidoidea is the second largest superfamily after Ichneumonoidea and they have a greater range of biological diversity than any other parasitic superfamily. They are mostly parasitoids but are also known to be phytophagous. Chalcids associated with plant galls can induce galls or can occur as parasitoids of gall-forming insects and, in some cases, exist as inquilines. A preliminary study was carried out in Karnataka, India during the year 2023--2024 to document the association of chalcid wasps with plant galls. During surveys, leaf galls were collected from Acacia chundra Rottler, Carissa spinarum L., Erythrina sp., Ficus racemosa L., Pongamia pinnata (L.), Terminalia arjuna (Roxb.), and two other undetermined plants. The galls were placed inside rearing containers and monitored for wasp emergence. It was observed that among the galls sampled, the gall niche was mostly utilised by members of the family Eulophidae (Subfamily: Tetrastichinae). In the present study, a pteromalid wasp—Cheiropachus sp.—was newly recorded from leaf galls of Carissa spinarum, and it is an interesting observation since members of genus Cheiropachus have only been recorded from Coleoptera (Bostrichidae, Cerambycidae, Curculionidae, and Scolytidae) hosts previously. A checklist of chalcid wasps and their associated plant galls is provided along with their likely host.