Agriotypus armatus Curtis, 1832, a parasitoid of Silo pallipes Fabricius, 1781: the first record for the Balkan Peninsula

Key-words: Agriotypus, parasitoid, Serbia, distribution, ecological parameters Among the diverse order of Hymenoptera, aquatic species are of special interest. During macrozoobenthos sampling in the rivers of Serbia in 2003 and during the period 2011−2012, pupae of Silo pallipes Fabricius, 1781 were recorded which were parasitized by an ichneumonid wasp Agriotypus armatus Curtis, 1832, this being the first record of it for the Balkan Peninsula. A total of 217 A. armatus specimens were collected at 29 localities situated along 16 watercourses of Serbia. All four parasitoid stages (egg, larva, pupa and resting adult) were recorded. The identity of the parasitoid was confirmed using standard molecular methods. This study also focuses on the ecology of the parasitoid and its host. The widespread distribution of A. armatus in Europe suggests the presence of this species in other Balkan countries, but this has not yet been confirmed due to a lack of surveys and/or the constantly increasing pollution of freshwaters.