Parasitoids (Hymenoptera: Chalcidoidea) associated with oak gall wasps (Hymenoptera: Cynipidae) in northeastern Algeria

Cynipid galls on oak (Fagaceae: Quercus) are natural microcosms that support many insect species, including the gall inducers (Hymenoptera: Cynipidae, Cynipini), cynipid inquilines, and chalcid parasitoids (Hymenoptera: Chalcidoidea). Little is known about these communities in North Africa, and here we report the results of the first systematic surveys in northeastern Algeria. Thirteen Cynipini species gall generations were reared from 999 galls on Quercus suber L. and Q. faginea Lam. collected between 2022 and 2024.

A total of 242 parasitoids representing 19 chalcid species in seven families were reared, six of which (Aulogymnus trilineatus (Mayr), Eurytoma setigera Mayr, Sycophila iracemae Nieves-Aldrey, Sycophila variegata (Curtis), Ormyrus pomaceus (Geoffroy), and Torymus affinis (Fonscolombe)) are recorded for the first time from North Africa. Similarities in parasitoid assemblage composition between cynipid galls with similar morphology that develop on the same host tree organ, and differences among host galls that differ morphologically, structurally, and phenologically are documented, corroborating previous research.