The curculionid beetle Curculio elephas (Gyll.) is broadly represented in holm oak forests in the Montes de Toledo area of Ciudad Real (central Spain) in whose acorns it reproduces. This species is attacked by some natural enemies among which the braconid hymenopteran Schizoprymnus longiseta (Herrich-Schaeffer) stands out, and this is the only parasite found in the study area. The paper includes data about its biology, behaviour, degree and type of parasitism on C. elephas. Such information was unknown until now and confirms the hypothesis that Schizoprymnus species are solitary ovo-larval parasites. Curculio elephas (Curculionidae) : Host, Parasite Schizoprymnus longiseta (Braconidae) : Parasite Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Habitat; Terrestrial habitat; Land zones; Palaearctic region; Eurasia; Europe Curculio elephas; Hymenopteran parasites; Parasite biology; plant host; forest; Schizoprymnus longiseta; Plant hosts; Holm oak; Forest and woodland; Spain; Ciudad Real, Montes de Toledo Schizoprymnus longiseta; Coleopteran hosts; Parasite biology; plant host; forest; Curculio elephas; Forest and woodland; Spain; Ciudad Real, Montes de Toledo none