Abstract: Bactericera gobica (Loginova) is an important pest of medlar (Lycium barbarum L.), that can attack buds or tender leaves, causing damage as early leaf drop and fruit drop, and leading to big economic loss. In the investigation of natural enemies conducted in Zhongwei, Ningxia, China, we discovered a species of Psyllaephagus, P. arenarius Trjapitzin, which attacks B. gobica and has high parasitism rate. This is the first record of P. arenarius from China, and B. gobica also a new host record for P. arenarius. In this paper, the species P. arenarius was redescribed and illustrated with photomicrographs.

Key words: Encyrtidae, Psyllaephagus arenarius, Lycium barbarum, Bactericera gobica, parasitoid wasp, new record, China