Eggs of Perlidae (Insecta, Plecoptera) of the Russian Far East Author Teslenko, Valentina A. text Zootaxa 2024 2024-12-11 5551 1 91 115 https://doi.org/10.11646/zootaxa.5551.1.3 journal article 10.11646/zootaxa.5551.1.3 1175-5326 14389957 8898D059-5E78-451F-8646-D47D4A1A8BE9 Oyamia nigribasis Banks, 1920 Figs. 69−75 Material examined . Russia , Far East , Amurskaya Oblast : 1♀ , Bureya River near Novobureysk , left bank, Amur River basin, 12.07.2012 , coll. V . Teslenko ; Jewish Autonomous Oblast : 1♀ , Bastak Nature Reserve , Glinyanka River , light trap , 11.07.2018 , coll. T . Vshivkova ; Primorsky Krai : 4♀ , Pasechnaya River , Kievka River basin, Lazo settlement, 24.07.2005 , coll. Yu. Sundukov ; 12♂ , 7♀ , Komissarovka River near Dvoryanka village , Khanka Lake basin, 25.06.2015 , coll. V . Lyubaretz ; 5♂ , 11♀ , Shumnaya River , Ussuri River basin, Amur River basin, near Shumnyi settlement, 26.06.2017 , coll. V . Lyubaretz ; 1♂ , 1♀ , Bolshaya Ussurka River , Amur River basin, Melnichnoe village , 7.07.2013 , coll. V . Lyubaretz . Egg . Oval but slightly asymmetrical ( Figs. 69, 74 ), dark brown, total length 446−390 μm, equatorial width 317−291 μm (n=3). Collar short, stalked, rim flanged, and irregularly incised; sides of collar with irregularly spaced ridges reaching the shoulders and forming a single row of prolonged, hexagonal, smooth, and shallow cells ( Figs. 69, 71, 74 ). Anchor is umbrella-like; the surface is composed of hexagonal units with globular bodies (2–9) grouped inside and distributed over the whole area of the anchor plate ( Fig. 70 ); the edge of the anchor plate has a row of triangular projections bearing the single globular bodies ( Fig. 70 ). The cleaned chorion is smooth, with indistinct follicular cell impressions over the whole surface ( Figs. 69, 72 ). The structure on the extrachorion membrane with hexagonal FCI’s bearing a few (2−4) large adhesive mushroom bodies over each follicle cell impression ( Figs. 74−75 ). The micropylar line is closer to the anterior pole; micropylar canals are tunnel-shaped, long, and slightly slanted; sperm guides open; orifices have slightly raised rim ( Figs. 69, 73 ). On the extrachorion layer, micropylar orifices are surrounded by rosettes of FCI’s that resemble flowers ( Fig. 75 ). Comments. The egg of O. nigribasis is generally similar to that of O. lugubris ( McLachlan, 1875 ) , but the chorionic surface of that species at the shoulder area is covered with two rows of hexagonal, smooth, and deep cells with raised walls ( Isobe & Uchida 2009 ). Distribution : East Asian mainland species with distribution limited to the south of the Russian Far East (Amurskaya Oblast, south Khabarovsk Krai, and Primorsky Krai), China ( Huo et al. 2022 ), North Korea ( Zwick 1973 ), and South Korea (Stark 2010).