53 Chalcid wasps of the family Encyrtidae (Hymenoptera, Chalcidoidea) from Oslo Municipality, Norway, with description of a new species GEORGE JAPOSHVILI & LARS OVE HANSEN Japoshvili, G. & Hansen, L.O. 2017. Chalcid wasps of the family Encyrtidae (Hymenoptera, Chalcidoidea) from Oslo Municipality, Norway, with description of a new species. Norwegian Journal of Entomology 64, 53–60. This contribution focuses on the family Encyrtidae from Oslo Municipality, one of the richer areas in Norway as biodiversity concerns. The following four species are reported for the frst time from Norway: Metaphycus punctipes (Dalman, 1820), Protyndarichoides aligarhensis (Fatma & Shafee, 1985), Psyllaephagus belanensis (Hofer, 1963) and Trechnites trjapitzini Sugonjaev, 1968, and one additional species, Blastothrix osloensis sp. n., is described and illustrated. This brings the total number of Norwegian encyrtids up to 141, and 30 of these are recorded from Oslo Municipality. Comments on biology and distribution of the species are given. The aim of this study is to highlight the distribution of Encyrtidae in Norway, and to provide a complete list of the Norwegian species. Key words: Hymenoptera, Chalcidoidea, Encyrtidae, Blastothrix osloensis, new species, Norway, Oslo municipality, Malaise traps, Hemiptera, Coccoidea, Psylloidea, scale insects. George Japoshvili [corresponding author], Institute of Entomology, Agricultural University of Georgia, David Agmashenebeli Alley #240, 0159, Tbilisi, Georgia. E-mail: g.japoshvili@agruni.edu. ge. [Invertebrate Research Center, Agladze #26, Tbilisi-0119, Georgia] Lars Ove Hansen, Natural History Museum, University of Oslo, P.O. Box 1172 Blindern, NO-0318 Oslo, Norway. E–mail: l.o.hansen@nhm.uio.no Introduction The chalcid family Encyrtidae represents one of the most important agents in biological control of insects occurring as plant pests. They are, together with the family Aphelinidae, successfully used against many pest species, especially scale insects (Hemiptera, Coccoidea) (Noyes 1985, Nikolskaya & Yasnosh 1966). More than 400 species have been used worldwide as biological control agents of insect pests (Greathead 1986, Neueschwander et al. 1990, Noyes 1985, 2017). Parasitoids like encyrtids are the major component of many terrestrial ecosystems and may constitute up to 20% of all insect species (LaSalle & Gauld 1991, Godfray 1994, Memmot et al. 1994). This is the eight publication on Norwegian Encyrtidae based on the collections at the Natural History Museum of Oslo. The previous papers are Hansen et al. (2012), Japoshvili et al. (2013), Japoshvili & Hansen (2013, 2014, 2015) and Hansen & Japoshvili (2013, 2015). The aim of these contributions is to highlight the distribution of the family Encyrtidae in Norway, and fnally provide a catalogue of Norwegian Chalcidoidea. Five species hitherto not reported from Norway are presented, including one species new to science. © Norwegian Journal of Entomology. 29 June 2017