47 Fauna norvegica 2020 Vol. 40: 47–92. A review of grass flies (Diptera, Chloropidae) of Karelia and Murmansk Province of Russia Emilia P. Nartshuk 1 , Alexei V. Polevoi 2 and Andrey A. Przhiboro 1 Nartshuk EP, Polevoi AV and Przhiboro AA. 2020. A review of grassflies (Diptera, Chloropidae) of Karelia and Murmansk Province of Russia. Fauna Norvegica 40: 47–92. One hundred and sixteen species of Chloropidae (Diptera) are recorded in Russian Karelia and Murmansk Province: 112 in Karelia and 44 in Murmansk Province. Twenty-two and seven species are new for Karelia and Murmansk Province, respectively. Calamoncosis oscinella is for the first time reported from Russia and Elachiptera breviscutellata - from European Russia. Pseudogaurax venustus is reinstated as Gaurax venustus. Taxonomic notes are provided on Eribolus nana, Polyodaspis ruficornis, Oscinella vindicata and Cetema simile. The distribution and biological data are given for every species. Point maps are provided for species with at least one exactly known location. The zoogeographical structure of Chloropidae fauna on the examined territories is briefly discussed and compared with other north-European countries. doi: 10.5324/fn.v40i0.3406. Received: 2020-02-11. Accepted: 2020-06-01. Published online: 2020-07-02. ISSN: 1891-5396 (electronic). Keywords: Diptera, Chloropidae, fauna, Karelia, Murmansk Province, Russia. 1. Zoological Institute of Russian Academy of Sciences, Universiterskaya nab. 1, 199034 St Petersburg, Russia 2. Forest Research Institute of Karelian Research Centre of the Russian Academy of Sciences, Pushkinskaya 11, 185910 Petrozavodsk, Russia Corresponding author: Alexei Polevoi E-mail: alexei.polevoi@krc.karelia.ru The status of grass flies as a bioindicator group is questionable. It has been demonstrated that they are insensitive to fluorine- and sulphur- containing aerial emissions (Kozlov & Zvereva 1997), however, some authors mentioned increasing density of herbivorous flies including Chloropidae in polluted areas (Dabrowska-Prot 1984; Bährmann 1985). Chloropids are among the commonest flies in the examined regions and are found in almost all habitats. The first list of Karelian Chloropidae containing 17 species dates to the mid-19th century (Chydenius & Furuhjelm 1859). Frey (1934) recorded 29 species from Karelia and 17 species from Murmansk Province. Kanervo (1942) reported Oscinella frit (Linnaeus 1758) and Chlorops pumilionis (Bjerkander 1778) as pests of cereals in Karelia. Znamenskaya (1941, 1962) recorded Oscinella frit also from Murmansk Province. Krogerus (1960) recorded 12 species identified by Frey from bogs in the biogeographical province Regio Kuusamoensis (Paanajärvi and environs), with most of localities situated along the modern Russian-Finnish border or in Russia. Species from both Karelia and Murmansk Province are mentioned in several works (Nartshuk 1998, 1999a; Nartshuk & Przhiboro, 2003). Additional data on Karelian Chloropidae can be found in numerous local lists (Polevoi 1997, 2006; Yakovlev et al. 2000; Polevoi & Humala 2003, 2005, 2007, 2009; Humala & Polevoi 2006, 2008, 2009; Jakovlev et al. 2014). Two species in the genera Chlorops and Incertella have been described based on the materials from Russian Karelia (Duda 1933; Nartshuk & Przhiboro 2009). Up to now, no INTRODUCTION The Chloropidae (Diptera, Brachycera, Acalyptratae) is one of the largest acalyptrate families. The family is usually named as grass flies or frit flies. The family is species-rich, nearly 3200 valid species are known in the World (M. von Tschirnhaus pers. comm.) and more than 700 species in the Palaearctic. Chloropidae are distributed worldwide and represented in a great variety of habitats including forests, meadows, wetlands, swamps, bogs, marshes and steppe. The larvae are phytophagous, saprophagous, mycetophagous or carnivorous. The ability of grass-flies to utilize variable substrates made them a family of great ecological importance. Phytophagous larvae develop in the shoots and seeds of Poaceae or in the stems of other plants. Some species in the genera Oscinella, Chlorops, Lasiosina, Meromyza, and Dicraeus are economically important pests of cereals. Saprophagous larvae live in the plant tissues previously damaged by other insects, in fungi or decaying wood with mycelia, in bird nests, in excrements and animal corpses. Carnivorous larvae develop in the egg cocoons of spiders (Araneae) or egg pods of grasshoppers, locusts (Acrididae), mantids (Mantidae), or egg masses of whip spiders (Amblypygi) and dobsonflies (Megaloptera). A few species are predatory on root aphids (Pemphigidae) or thrips (Thysanoptera). Ferrar (1987) and Nartshuk (2014) give extended reviews of larval biology of Chloropidae. Due to species richness and rather simple methods of collecting (sweep net, Malaise traps, color plates), this family is an excellent choice to monitor biodiversity in most terrestrial habitats.