taxonID	type	description	language	source
03C495232072FFBC4BAFFE67FCC59631.taxon	description	Figs. 1 ‒ 9	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFBC4BAFFE67FCC59631.taxon	materials_examined	Material examined. Russia, Siberia: Krasnoyarsk Krai, Khakassia: 3 ♀, 22 km NW of Shira Lake, Bely Iyus River, 2.07.2014, coll. A. Leley; 1 ♂, Rastorguikha River, Selenga R. Basin, Burkalsky protected area, 23.08.2018, coll. Matafonoff; 1 ♂ 1 ♀, Altai, Tuekta River, 05.09.2021, coll. L. Yanygina.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFBC4BAFFE67FCC59631.taxon	description	Egg. Shape oval, symmetrical, with anterior and posterior poles broadly rounded and a concave cross-section (Figs. 5 ‒ 6). Length 322 – 332, width at the equator of 234 – 239 µm (n = 2). Collar well developed, with raised longitudinal wavy carinae and small transverse projections (Figs. 1, 3); base with a thickened, wavy ridge wider than the apically flanged rim, so the collar appears multi-leveled from above (Figs. 1, 3, 5). Anchor mushroom-shaped, with small globular bodies concentrated into groups of five and located in a peripheral area along the anchor edge; top of the anchor deeply embedded (Figs. 2, 4). Follicle cell impressions (FCIs) near the collar range from elongated to hexagonal (Figs. 1 – 2, 5). Chorion covered with hexagonal FSCs with slightly thickened elevated ridges (Figs. 1 ‒ 2, 5 – 8); floors shallow with numerous (20) shallow pits (Figs. 1 ‒ 2, 5 – 8). Micropyles arranged singularly in a row on follicle cell ridges near the anterior ¼ of the egg (Figs. 1 ‒ 2, 6). Orifices oval and located on raised, tunnel-shaped, and relatively long sperm guides, some associated with FCI rosettes (Figs. 7 – 8). Eclosion line absent. The chorionic structure on an external membrane comprises hexagonal FCIs bearing scattered adhesive mushroom bodies along the perimeter of each cell (Fig. 9).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFBC4BAFFE67FCC59631.taxon	distribution	Distribution: East Palaearctic species with limited distribution in Russia, Siberia: Altai, Sayan, Transbaikalia. East Kazakhstan. Mongolia.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFBC4BAFFE67FCC59631.taxon	discussion	Remarks. Isoperla altaica eggs from Siberia are smaller in size than those from Mongolia (360 × 250 µm) and larger than those from East Kazakhstan (295 × 235 µm) (Zwick & Surenkhorloo 2005). Apparently, the Siberian eggs imaged here are quite mature since their chorion is completely covered by FCIs. According to the available data obtained in transmitted light, the structure of the eggs from Kazakhstan is finely punctured, whereas the chorion of Mongolian eggs is unstructured (Zwick & Surenkhorloo 2005).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFB94BAFFA53FB0391A9.taxon	description	Figs. 10 – 17	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFB94BAFFA53FB0391A9.taxon	materials_examined	Material examined. Russia, Far East, Khabarovsk Krai: 1 ♂, Anyuisky National Park, Gassi Lake, Anyui River basin, Amur R. basin, 4.06.2019, N. Yavorskaya; 1 ♀, same locality, Anyui R., Adzhu Channel, 4.06.2019, coll. N. Yavorskaya; 2 ♀, same locality, Solomi R., Anyui R. basin, 3.06.2019, coll. N. Yavorskaya; Amurskaya Oblast: 6 ♂ 3 ♀, Bol’shiye Simichi River, Bureya R. basin, Amur R. basin, 9.06.2013, coll. V. Teslenko; 1 ♀, Zeya River, Ovsyanka settlement, Amur R. basin, 7.07.2015, coll. T. Tiunova; 1 ♂ 1 ♀, Dikan River, near the auto bridge, 27.07.2015, coll. V. Teslenko; Primorsky Krai: 1 ♀, Lazovsky Nature Reserve, Proselochnaya River, Proselochnaya cordon, Partizanskaya R. basin, 22.05.2007, coll. O. Zorina; 2 ♀, same locality, Staro-Kamensky stream, near Staraya Kamenka settlement, 28.05.2004, coll. Eu. Makarchenko; 1 ♂ 1 ♀, Bolshaya Ussurka River, Ussuri R. basin, Amur R. basin, settlement Zvenigorodka, 06.08.2004, coll. V. Teslenko; 1 ♂ 2 ♀, Ussuri River, Kamenka village, 07.05.1993, coll. V. Teslenko; 8 ♂ 8 ♀, Barabashevka River, near fish factory, 30.04.2003, coll. V. Teslenko.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFB94BAFFA53FB0391A9.taxon	description	Egg. Shape oval, symmetrical, with anterior and posterior poles broadly rounded and a concave cross-section (Figs. 10 ‒ 11, 14); chorion thickness 2.9 ‒ 5.3 µm. Length 314 – 346 µm, width at the equator 237 – 261 µm (n = 6). Collar well developed, with irregular longitudinal ridges; rim deeply serrated and curved outward; collar surrounded by slightly pronounced shoulder without ring (Figs. 11, 13, 15). Anchor mushroom-shaped, with small grouped globular bodies placed along a peripheral area of the anchor edge (Figs. 10, 12). Chorion surface is rough, covered with hexagonal follicle cell impressions with thick, slightly elevated ridges (Figs. 10 ‒ 11, 14, 16 – 17); floors with numerous (9 – 11) deep groove-like pits (Figs. 16 ‒ 17). Eclosion line absent. Micropyles located along ridges, FCI in the anterior ¼, and faintly noticeable (Figs. 10, 14). Micropylar canals straight or slightly sloping, tunnel-shaped, and relatively long; canals raised slightly above the surface (Fig. 17). Orifices the same size as FCI pits.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFB94BAFFA53FB0391A9.taxon	distribution	Distribution. East Palaearctic species. Russia, Siberia: Altai, East Sayan, Baikal Lake basin, Transbaikalia; Far East: Amurskaya Oblast, Jewish Autonomous Region, Khabarovsk Krai, Primorsky Krai, Sakhalin Island. East Kazakhstan. Mongolia. China, Inner Mongolia Autonomous Region (Huo et al. 2020).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232072FFB94BAFFA53FB0391A9.taxon	discussion	Remarks. The shape, size, and chorion structure of the egg as a whole correspond to the first description by Zwick & Surenkhorloo (2005). Egg bears a specific collar with a serrated rim; the chorion structure appears as FCI’s with thick elevated ridges, their floors covered with numerous (9 – 11) deep groove-like pits.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232077FFB94BAFFD2BFB299495.taxon	description	Figs. 18 – 27	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232077FFB94BAFFD2BFB299495.taxon	materials_examined	Material examined. Russia, Far East, Khabarovsk Krai: 1 ♂, Bol’shaya Uda River, 18.08.2021, N. Yavorskaya; 1 L, Bol’shaya Del’ya River, 11.07.2022, coll. I. Tiunov; 1 ♂, Bol’shaya Del’ya River, 12.08.2022, coll. I. Tiunov; 1 ♂, Malaya Del’ya River, downstream, 5.08.2022, coll. I. Tiunov; Jewish Autonomous Region: 1 L, Nature Reserve Bastak, Bol’shoy Sorennak River, near the bridge to the Kukan, 11.07.2018, coll. T. Vshivkova; 1 ♂ 1 ♀, Kuldur River, Kuldur settlement, above the spring, Amur R. basin, 17.08.2024, coll. N. Yavorskaya; 2 ♀, Bastak Nature Reserve, Bastak River, Amur R. basin, 14.08.2024, coll. N. Yavorskaya. Japan, Hokkaido: 1 ♂ 1 ♀ 5 L, Tobetsu River, 43 ° 28.67 N 144 ° 17.65 E, 10.09.1995, coll. G. Kraft; 1 ♀, Shiretoko Pass Summmit, near Rausu, 44 ° 3.2 N 145 ° 6.2 E, 11.09.1995, coll. G. Kraft; 2 ♀, Soukippkaononai River near Shibetsu town, 43 ° 44.4 N 144 ° 53.6 E, 12.09.1995, coll. G. Kraft; 9 ♀, trib. Churui River, at bridge near Shibetsu town, 44 ° 43.7 N 144 ° 48.4 E, 12.09.1995, coll. G. Kraft; 1 ♀, 1 L, trib. Ikushina River, near Shibetsu town, 43 ° 48.1 N 144 ° 46.9 E, 12.09.1995, coll. G. Kraft.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232077FFB94BAFFD2BFB299495.taxon	description	Egg. Shape oval; marginally asymmetrical, anterior pole is rounded more widely than posterior pole (Fig. 18), and a concave cross-section (Fig. 20). Length 345 – 349 µm, width at equator 222 – 227 µm (n = 2). Collar well developed, with irregular longitudinal ridges and a flanged and incised rim; base of collar surrounded by a wide smooth shoulder limited by a ring (Figs. 19 – 20). Anchor mushroom-shaped, with small grouped globular bodies covering the entire surface of anchor evenly (Figs. 18 – 19). Follicle cell impressions near the collar ranged from subrectangular to hexagonal (Figs. 18, 20). Chorion covered with hexagonal FCIs with thick elevated ridges (Figs. 18, 21 ‒ 23); floors with numerous (ca. 37 – 39) very shallow and small pits (Figs. 22 ‒ 23). Micropylar row well visible along anterior ⅓ (Figs. 18, 21). Micropyles located near paired ridges and surrounded with rosettes of FCIs (Figs. 18, 21, 23). Micropylar canals straight, tunnel-shaped, and relatively long; orifices set in small oval cup-like depressions with long, smooth, slanted, and open sperm guides extending from cup rims (Figs. 18, 21, 23).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232077FFB94BAFFD2BFB299495.taxon	discussion	Remarks. The egg of I. eximia is described here for the first time. Eggs from Japan (Figs. 24 – 27) and the Russian Far East are similar in size (330 – 357 µm long, 177 – 207 µm wide, n = 4), have a collar with a smooth shoulder at the base, limited by a raised ring (Fig. 25), and have a similar chorion structure (Figs. 26 – 27). The main difference between Japanese eggs is their oblong shape (Figs. 18, 24). It is possible that the shape and appearance of eggs from the Japanese population vary depending on the degree of hydration. Eggs from dried Japanese females appear almost parallel-sided and narrow.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232077FFB94BAFFD2BFB299495.taxon	distribution	Distribution. East Palaearctic. Russia, Siberia: Altai, Sayan, Transbaikalia; Far East: Southern Yakutia, Amurskaya Oblast, Jewish Autonomous Region, Khabarovsk Region, Primorsky Krai, Sakhalin, and South Kuril Isles. East Kazakhstan (Devyatkov 2022). Mongolia. China (Changbai Mountain and Jilin Province) (Wang et al. 2018, Chen et al. 2019). Isoperla eximia is recorded from Japan (Hokkaido) for the first time.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232075FFBB4BAFFB71FE709443.taxon	description	Figs. 28 – 34	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232075FFBB4BAFFB71FE709443.taxon	materials_examined	Material examined. Russia, Far East, Khabarovsk Krai: 1 ♂, Anyuisky National Park, Tormasu River, Anyui R. basin, Amur R. basin, 21.06.2018, coll. N. Yavorskaya; Primorsky Krai: 7 ♂ 7 ♀, Lazovka River, Partizanskaya R. basin, below the pass, under the bridge, 13.06.1998, coll. V. Teslenko; 9 ♀, Malinovka River, Ussuri R. basin, Amur R. basin, 10 km above the Pozhiga village, highway, 16.06.1998, coll. V. Teslenko.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232075FFBB4BAFFB71FE709443.taxon	description	Egg. The egg of I. flavescens is described here for the first time. Shape oval, symmetrical with anterior and posterior poles broadly rounded (Figs. 28 ‒ 29) and a concave cross-section (Fig. 32). Length of 287 – 302 µm and a width at the equator of 200 – 217 µm (n = 4). Collar well developed, with irregular longitudinal ridges extending onto the shoulder; shoulder contoured with a ring; rim incised and flanged (Figs. 29, 31 – 32). Anchor mushroom-shaped, with small grouped globular bodies covering the entire surface of the anchor evenly (Figs. 28, 30). FCIs near collar range from pentagonal to hexagonal (Fig. 32). Chorion covered with hexagonal FCIs with thick elevated ridges (Figs. 28 ‒ 29, 32 – 34); floors covered with deep pits, their number not exceeding 9 – 13 (Figs. 33 ‒ 34). Micropylar row visible near anterior ¼ (Fig. 29). Micropyles located near ridges and surrounded with rosettes of FCIs (Figs. 29, 34). Micropylar canals smaller than in other species; orifices and sperm guides weakly visible (Fig. 34).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232075FFBB4BAFFB71FE709443.taxon	distribution	Distribution. East Asian species with limited distribution in the south of the Russian Far East (Jewish Autonomous Region, Khabarovsk Krai, and Primorsky Krai). South Korea (Kim et al. 1998). China (Changbai Mountains) (Huo et al. 2022).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB54BAFFF46FF789736.taxon	description	Figs. 35 – 40	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB54BAFFF46FF789736.taxon	materials_examined	Material examined. Russia, Far East, Amurskaya Oblast: 5 ♂ 15 ♀, Bureya River, Amur R. basin, Novobureysk settlement, 27.06.2013, coll. V. Teslenko; 16 ♂ 19 ♀, Bureya River, Novobureysk settlement, above Podoshva island, 28.06.2013, coll. V. Teslenko; Khabarovsk Krai: 10 ♂ 17 ♀, Bikin River, Amur R. basin, 300 m below the bridge, Vladivostok-Khabarovsk highway, 18.06.2000, coll. T. Tiunova; Prymorsky Krai: 1 ♂, Razdolnaya River, Zagorodnoye settlement, 08.06.2019, coll. E. Gorovaya. Egg. Rhombus-shaped, uniformly tapered toward the anterior and posterior poles, with a cross-shaped ridge along the anterior ⅓; posterior pole cross-section triangular, with three distinct longitudinal ridges; anterior pole quadrangular with four longitudinal ridges; anterior end of egg is convex (Figs. 35, 37, 38). Length 269 – 290 µm, width widest at ⅓ from the anterior pole of 173 – 177 µm, thickness 2.4 μm (n = 2). Collar well developed, with short longitudinal ridges and a narrow flanged and slightly wavy rim; base covered with a mesh of empty cells of a smoothed triangular shape directed into interior of egg (Figs. 36 – 37, 39). Anchor mushroom-shaped, covered with small, globular bodies larger than other species (Fig. 36). Chorion near collar smooth, ranging downward from pentagonal to hexagonal FCIs with thick and elevated ridges; floors flat with numerous (ca. 19 – 29) punctations (Figs. 37 ‒ 38). Eclosion line absent. Micropylar row visible near the anterior ⅓ of egg (Fig. 35). Micropyles scattered in groups of 3 on FCI ridges and surrounded by rosettes of FCIs; orifices set in small oval cup-like depressions with short sperm guides (Fig. 40).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB54BAFFF46FF789736.taxon	distribution	Distribution. East Palaearctic species. Russia, West Siberia, West Altai, Sayan, Baikal Lake basin, Transbaikalia; Far East: Amurskaya Oblast, Jewish Autonomous Region, Khabarovsk Region, Primorsky Krai. East Kazakhstan (Devyatkov 2022). Mongolia. China, Northeast, including Changbai Mountain, Jilin Province (Chen et al. 2021). South Korea (Hwang & Muranyi 2020).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB54BAFFF46FF789736.taxon	discussion	Remarks. The original description of the egg indicates one of the diagnostic features — the shape of the collar. Collar with a few subdued meshes, edge simple, base smoothly bulging into interior of egg (Zwick & Surenkhorloo 2005).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB44BAFFB56FA8593D5.taxon	description	Figs. 41 – 47	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB44BAFFB56FA8593D5.taxon	materials_examined	Material examined. Russia, Far East, Amurskaya Oblast: 1 ♂ 2 ♀, Dikan River, Bureya R. basin, Amur R. basin, 1 km below auto bridge, 5 km from Novobureisk settlement, 10.07.2015, coll. T. Tiunova; Khabarovsk Krai: 1 ♂, Komsomolsk Nature Reserve, Bitki River, Udyl Lake, 13.07.2021, coll. N. Yavorskaya; Jewish Autonomous Region: 1 ♀, Bastak Nature Reserve, Scorpion’s Lair Stream, 29.07.2022, coll. T. Vshivkova; Primorsky Krai: 4 ♂ 3 ♀, Ussuri River, Amur R. basin, Stepanovka village, 26.06.1988, coll. V. Teslenko; 3 ♂ 4 ♀, Ussuri River, Kamenka village, 5.07.1993, coll. V. Teslenko; 1 ♂ 9 ♀, Shumnaya River, Ussuri R. basin, Shumny settlement, 29.06.2017, coll. V. Lyubarets. Egg. Rhombus-shaped, tapered toward the anterior and posterior poles; cross-shaped ridge present medially; posterior pole triangular in cross-section, with a distinct cross-shaped ridge on each side; anterior pole is quadrangular with four longitudinal ridges; anterior apex is convex (Figs. 41, 43, 46). Length 217 – 236 µm, maximum width medially 174 – 182 µm (n = 2). Collar low, longitudinal ridges short, their bases well visible dorsally (Figs. 42 – 44); collar sides between ridges covered with empty pits extending to rim, rim narrow and slightly wavy apically (Figs. 42, 44). Anchor mushroom-shaped and covered with globular bodies scattered in groups of 2 or 3, globular bodies larger than other species (Fig. 42). Chorionic surface covered with numerous, very shallow punctuations; hexagonal FCIs not visible, eclosion line absent (Figs. 44 – 45, 47). In addition to shallow punctations, there are small and tiny donut-shaped rounded knobs present on the chorion surface (Figs. 45, 47). Micropyles are positioned singularly or in a row of 3 near the anterior ⅓ of the egg (Fig. 41); orifices set in small oval cup-like depressions, and sperm guides are long and thin, weakly visible (Fig. 45).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB44BAFFB56FA8593D5.taxon	distribution	Distribution. East Palaearctic species. Russia, Siberia: Altai, Sayan, Baikal Lake basin, Transbaikalia; Far East: Amurskaya Oblast, Jewish Autonomous Region, Khabarovsk Region, Primorsky Krai. East Kazakhstan (Devyatkov 2022). Mongolia. China (Zhu et al. 2007).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207BFFB44BAFFB56FA8593D5.taxon	discussion	Remarks. In addition to the dimensions and characteristics of the chorion structure, the original description of the collar by Zwick & Surenkhorloo (2005) generally corresponds to the results obtained here by SEM.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFF46FC0A9712.taxon	description	Figs. 48 – 55	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFF46FC0A9712.taxon	materials_examined	Material examined. Russia, Far East, Khabarovsk Krai: 1 ♂, Anyuisky National Park, Bira Channel, Amur R. basin, 19.06.2018, coll. N. Yavorskaya; 9 ♂ 11 ♀, Anyuisky National Park, Anyui River, Nilo Chanell, at light, Amur R. basin, 23.07.2018, coll. Ev. Makarchenko; Primorsky Krai: 1 ♂, Barabashevka River, above the fish factory, 24.06.2021, coll. T. Tiunova; 1 ♂ 4 ♀, Ryazanovka River, cordon, 9.06.1998, coll. V. Lyubarets; 7 ♂ 9 ♀, Barabashevka River, near the fish factory, 9.06.2003, coll. V. Teslenko; 5 ♂ 4 ♀, Artemovka River near the Mnogoudobnoye settlement, 14.07.2002, coll. V. Lyubarets; 1 ♂ 2 ♀, Shumnaya River, Shumny settlement, Ussuri R. basin, Amur R. basin, 29.06.2017, coll. V. Lyubarets; 2 ♀, Lazovka River, Lazo settlement, Partizanskaya R. basin, 22.08.2006, coll. Shokhrin.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFF46FC0A9712.taxon	description	Egg. The egg of I. maculata is described here for the first time. Shape oblong, with a wide diameter closer to the posterior pole; a cross-shaped ridge near the equator dividing the anterior and posterior poles; posterior pole triangular in cross-section with an indistinct cross-shaped ridge on each side; anterior pole quadrangular in cross-section with four longitudinal ridges and apex slightly concave (Figs. 48 ‒ 51). Length 269 µm, maximum width nearer to posterior pole 165 µm (n = 1). Collar well developed, elevated with irregular and raised longitudinal ridges, rim widely flanged, wavy apically (Figs. 49 – 50, 54). Anchor mushroom-shaped, globular bodies concentrated into groups of 2 – 5, located mainly in a peripheral area along the anchor edge and top of the anchor deeply embedded (Figs. 48, 53). Chorion covered with hexagonal FCIs with thickened, elevated, and raised ridges and numerous (12 – 20) deep pits (Figs. 49, 55). Micropyles small, poorly distinguishable due to their similar size to the pits in hexagonal FCIs and arranged singularly in a row on follicle cell ridges near anterior ⅓ of the egg (Fig. 55). Orifices round and located on raised horizontal, tunnel-shaped relatively long sperm guides laterally; sperm guides weakly visible and unassociated with FCI rossetes (Figs. 52, 55). Eclosion line absent.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFF46FC0A9712.taxon	distribution	Distribution. East Asian species with limited distribution in the south of the Russian Far East, including the Jewish Autonomous Region, Khabarovsk Krai, and Primorsky Krai.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFBB2FA8D94BA.taxon	description	Figs. 56 – 62	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFBB2FA8D94BA.taxon	materials_examined	Material examined: Russia, Siberia, Krasnojarsky Krai, Khakassia: 1 ♀, 50 km NW of Shira Lake, Black Iyus River, 4.07.2014, coll. A. Leley; Transbaikalia: 1 ♂, Rastorguikha River, Selenga R. Basin, Burkalsky protected area, 23.08.2018, coll. Matafonoff; Altai Republic: 1 ♂, 1 ♀, Tuekta River, Ob River basin, 05.09.2021, coll. L. Yanygina. Mongolia, Arkhangai Aimak, Onder-Ulaan, Tsakhir: 2 ♀, Cenlnt gol. 48 ° 07 N 100 ° 22 E, 2100 m above sea level, 10 – 13.05.1997, coll. Yu. Marusik.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFBB2FA8D94BA.taxon	description	Egg. Shape oval, marginally asymmetrical with posterior pole narrower than anterior pole, anterior pole widely rounded, cross-section concave (Figs. 56, 59). Length 229 ‒ 260 µm, width at the equatorial region 175 ‒ 182 µm (n = 4). Collar well developed, elevated with irregular longitudinal ridges; base of collar deeply embedded and surrounded by a narrow smooth shoulder; rim flanged and wavy apically (Figs. 56, 58 – 59). Anchor mushroom-shaped, with small globular bodies concentrated into groups of 2 – 5 located mainly in a peripheral area along the anchor edge (Fig. 57). Follicular cells near the collar ranged from pentagonal to hexagonal (Fig. 56). Chorion covered with hexagonal FCIs with thickened, slightly elevated ridges and numerous (12 – 20) deep pits (Figs. 60 ‒ 62). Micropyles positioned singularly along one row on follicle cell ridges near the anterior ⅓ (Fig. 60). Orifices set in small, oval, cup-like depressions; sperm guides tunnel-shaped and relatively long and wider than ridges and are associated with FCI rosettes (Figs. 56, 60 – 62). Eclosion line absent.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFBB2FA8D94BA.taxon	distribution	Distribution. East Palaearctic species originally described from Mongolia (Onon River basin). The species is also known from Russia in the rivers of East and West Siberia, including Altai, the Baikal Reserve, and the Selenga River Basin. East Kazakhstan (Devyatkov 2022).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232078FFB64BAFFBB2FA8D94BA.taxon	discussion	Remarks. The original description clearly indicates the size and shape of the egg, as well as the chorion structure with deep, large pits and their unclear location in polygonal fields (Zwick & Surenkhorloo 2005). The collar and anchor were also described, which generally corresponds to the SEM results presented here.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFB34BAFFF46FE29956F.taxon	description	Figs. 63 – 70	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFB34BAFFF46FE29956F.taxon	materials_examined	Material examined: Russia, Siberia, Republic of Buryatiya: 6 ♂ 3 ♀, Selenga River, 6 km from the Selenga Pulp Mill, 5.06.2007, coll. N. Bazova; 2 ♂ 1 ♀, Selenga River, Tologoy Rock, 09.07.2007, coll. N. Bazova; 7 ♂ 5 ♀, Chikoy River, settlement Povorot, Selenga R. basin, 8.06.2009, coll. N. Bazova; 15 ♂ 17 ♀, Selenga River, settlement Tataurovo, 1.07.2009, coll. N. Bazova; 22 ♂ 16 ♀, Selenga River, above confluence with Chikoy River, railway bridge, 3.07.2009, coll. A. Basov and N. Basova; Far East, Yakutiya: 4 ♂ 5 ♀ 4 L, Aldan River, Lena R. basin, 10 – 13.08.1987, coll. V. Bogatov; Amurskaya Oblast: 12 ♀, Zeya River, Amur R. basin, Ovsyanka settlement, 3.07.2013, coll. V. Teslenko; 2 ♀, Zeya River, upstream, near Mazanovo settlement, Amur R. basin, 5.08.2006, coll. T. Tiunov; 6 ♀, Zeya River, near Krasnoyarovo settlement, 24.06.2004, coll. V. Teslenko; 4 ♂ 2 ♀, Zeysky Nature Reserve, Gramatukha River, Zeya River basin, 9.09.2007, coll. E. Makarchenko; 6 ♂ 25 ♀, Zeya River, mouth, Blagoveshchensk, 22.06.1997, coll. T. Arefina; 5 ♂ 7 ♀, Zeya River, Alekseyevka-Alexandrovka settlement, Amur R. basin, 8.07.2013, coll. V. Teslenko; Khabarovsk Krai: 1 ♀, Bureya River, 10 km below the mouth of the Urgal River, Amur R. basin, 18.07. 2003, coll. T. Tiunova; 3 ♀, Tunguska River, near Danilovka settlement, Amur R. basin, 26.06.2007, coll. V. Teslenko; 3 ♂, 6 L, Amur River, Susanino settlement, 23 – 26.06.2000, coll. T. Tiunova; 2 ♀, Amur River, Zimmermanovka settlement, 18.06.2005, coll. T. Tiunova; 1 ♂ 1 ♀, stream without name in Amur R. basin, 2.07.2006, coll. N. Yavorskaya; Chukotka Autonomous Okrug: 1 ♀, Anadyr River basin, 31.07.1982, coll. I. Chereshnev.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFB34BAFFF46FE29956F.taxon	description	Egg. Shape oval, marginally asymmetrical with the posterior pole narrower than anterior one, which is widely rounded, cross-section concave (Figs. 63 – 64). Length 232 ‒ 246 µm, width at equator 165 ‒ 171 µm (n = 3), chorion thickness 2.6 µm. Collar well developed, elevated with irregular and raised longitudinal ridges; base of collar embedded; ring around collar base short and slightly rough; rim flanged and wavy apically (Figs. 63, 65). Anchor mushroom-shaped with globular bodies concentrated into groups of 2 ‒ 5, mainly in a peripheral area along the anchor edge (Figs. 64, 66). Chorion structure with faintly visible hexagonal FCIs and ridges; chorionic surface smooth, evenly covered with numerous, small, and deep pits (Figs. 63 – 64, 67 – 69). Micropyles arranged singularly along one row near the anterior ⅓ of the egg and grouped in threes (Figs. 63, 67). Orifices present in oval, cup-like depressions; sperm guides are tunnel-shaped and visible (Fig. 69); in the Far Eastern population, the chorion is smooth without punctations around the orifices (Fig. 70). Eclosion line absent.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFB34BAFFF46FE29956F.taxon	distribution	Distribution. Transpalaearctic species was originally described from Lapponia (Umensis ad Umenaes, Sweden) and found in streams and large rivers in the northern part of the Palaearctic Region. Europe: Norway, Finland, Austria, Switzerland, France, Germany, Italy, and very rarely in the Balkan Region, including Croatia. Bulgaria. Russia: North-East, Komi Republic, and Nenets Autonomous Okrug; Asia, Siberia: Krasnojarski Krai, Altai, Sayan, and Transbaikalia; Far East: Southern Yakutia, Magadanskaya Oblast, Amurskaya Oblast, Jewish Autonomous Region, Khabarovsk Krai, Primorsky Krai, and Chukotka Autonomous Okrug. East Kazakhstan (Devyatkov 2022). Mongolia.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFB34BAFFF46FE29956F.taxon	discussion	Remarks. The eggs of the species vary slightly in size across its wide trans-Palaearctic range. The egg size ranges from 252 – 268 × 169 – 177 µm for the Mongolian specimen to 276 – 289 × 194 – 202 µm for the Norwegian specimen (Zwick & Surenkhorloo 2005) and 232 – 246 × 165 – 171 µm in specimens from the Russian Far East. The anchor is rarely observed in eggs of the Far Eastern population. The chorion thickness was 4 µm for the Mongolian (Zwick & Surenhkorloo 2005) and 2.6 µm in the Far Eastern specimens. Minor differences were also noted in the chorion punctuations surrounding the micropyle of the eggs from Siberia (the Selenga River basin) and Far Eastern specimens (Figs. 69 – 70).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFAC4BAFF962FC0A913D.taxon	description	Figs. 71 – 80	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFAC4BAFF962FC0A913D.taxon	materials_examined	Material examined. Russia, Far East, Primorsky Krai: 4 ♀, Komissarovka River, Khanka Lake basin, near Dvoryanka village, 23 – 25.06.1994, coll. Bulavsky; 1 ♀, Barabashevka River, light trap, 06.07.2021, coll. E. Gorovaya; 4 ♂ 4 ♀, Komissarovka River, Komissarovo village, 28 – 29.05.1998, coll. V. Teslenko; 1 ♂ 1 ♀, Tigrovaya River, opposite Khmelnitskie Shcheki, Partizanskaya R. basin, 11 06.1998, coll. V. Teslenko; 1 ♂ 1 ♀, Razdolnaya River near Fadeyevka village, 31.05.1998, coll. T. Vshivkova; 1 ♂, 1 ♀, Razdolnaya River, near the border with China, coll. T. Vshivkova; 4 ♂ 6 ♀, Shkotovka River, 25 – 29.05.2015, reared, V. Teslenko.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFAC4BAFF962FC0A913D.taxon	description	Egg. The egg of I. ornata is described here for the first time. Egg pear-shaped, posterior ⅔ triangular in cross-section, anterior ⅓ square, with distinct cross-shaped ridges (Figs. 71 – 72, 78 – 79); anterior pole square, slightly concave (Fig. 78). Length 263 ‒ 269 µm, width 181 ‒ 192 µm (n = 5), chorion thickness 3.1 µm. Collar well developed, elevated with irregular and raised longitudinal ridges; rim flanged, serrated, or wavy; collar base offset with pits (Figs. 74 – 75). Anchor mushroom-shaped, with small globular bodies concentrated into groups of 2 – 5 and located mainly in a peripheral area along the anchor edge, top deeply embedded and covered with single globular bodies; anchor covers the collar completely (Fig. 73). Hexagonal FCI’s ridges slightly raised and thickened, floors flat with numerous (about 16) punctations (Fig. 80); eclosion line absent. Micropyles small and weakly visible, arranged singularly on follicle cell ridges near the anterior ⅓ of the egg (Fig. 77). Orifices set in small, oval, cup-shaped depressions; sperm guides poorly visible (Figs. 71 – 72, 77).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C49523207DFFAC4BAFF962FC0A913D.taxon	distribution	Distribution. East Asian species with limited distribution in the south of the Russian Far East, including the Jewish Autonomous Region, Khabarovsk Krai, and Primorsky Krai.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFAC4BAFFD5FFCD896C1.taxon	description	Figs. 81 – 89	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFAC4BAFFD5FFCD896C1.taxon	materials_examined	Material examined. Russia, Far East, Primorsky Krai: 1 ♂, Barabashevka River, above the fish factory, 24.06.2021, coll. T. Tiunova; 3 ♂, Barabashevka River, the same place, 31.05.2004, coll. V. Teslenko; 2 ♂ 4 ♀ 3 L, Barabashevka River the same place, 14 – 23.05.2002, coll. V. Teslenko; 5 ♂ 7 ♀, Ryazanovka River, near the hunting grounds, 10.06.2003, coll. V. Teslenko; 3 ♂ 2 ♀, Bolshaya Ussurka River, Zvenigorodka village, Ussuri R. basin, 06.08.2004, coll. V. Teslenko; 2 ♂ 4 ♀ 1 L, Tigrovaya River, Partizanskaya R. basin, Khmelnitskoye settlement, 11 06.1998, coll. V. Teslenko; 2 ♂ 4 ♀, Sergeevka River, Partizanskaya R. basin, highway, under the bridge, 12.06.1998, coll. V. Teslenko.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFAC4BAFFD5FFCD896C1.taxon	description	Egg. The egg of I. pseudornata is described here for the first time. Shape oval, sometimes pear-shaped (Figs. 81 – 82); cross-section pentagonal with 5 distinct longitudinal ridges; posterior and anterior poles are pentagonal, and the anterior pole is slightly concave (Figs. 85 – 87). Length 242 ‒ 329 µm, width 203 ‒ 229 µm (n = 5). Collar well developed and relatively high, with irregular and raised longitudinal ridges; rim flanged, wavy at the apex; base embedded, shoulder smooth, and surrounded with a row of pits (Figs. 82, 84, 87). Anchor mushroom-shaped, with small globular bodies concentrated into groups mainly in a peripheral area along the margin’s top of the anchor, shallowly embedded and covered with a few single globular bodies (Figs. 81, 83). Hexagonal FCIs well-developed, ridges wide, rose, rough, and thickened floors rough with numerous relatively deep punctations (about 14 – 19); eclosion line absent (Figs. 82, 88). Micropylar row clearly visible, with micropyles set on follicle cell ridges and grouped in threes near the anterior ⅓ (Fig. 82). Orifices arranged singularly on the top of FCI ridges, larger than the chorionic punctations (Fig. 89) and surrounded by polygonal rosettes; sperm guides short and thickened (Fig. 89).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFAC4BAFFD5FFCD896C1.taxon	distribution	Distribution. East Asian species with limited distribution in the south of the Russian Far East, Jewish Autonomous Region, Khabarovsk Krai, and Primorsky Krai.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFA94BAFF9C3FB5F90A5.taxon	description	Figs. 90 – 98	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFA94BAFF9C3FB5F90A5.taxon	materials_examined	Material examined: Russia, Far East, Amurskaya Oblast: 3 ♂ 5 ♀, Norsky Nature Reserve, Nora River, cordon near Berezovoye Lake, Selemdzha-Zeya-Amur R. basins, 16.06.2004, coll. V. Teslenko; 5 ♂ 6 ♀, Tom River, under the bridge, Amur R. basin, 13.06.2004, coll. V. Teslenko; 1 ♀, Deya River, Bureya R. basin, Amur R. basin, 4.07.2014, coll. V. Teslenko; 3 ♂ 10 ♀, Dzhilimkur River, Zeya R. basin, Amur R. basin, high way bridge, 8.07.2013, coll. V. Teslenko; 3 ♀, Dikan River, under high way bridge, Bureya R. basin, Amur R. basin, 28.06.2014, coll. V. Teslenko; Khabarovsk Krai: 2 ♂ 3 ♀, Bolshoy In River, Tunguska R. basin, Amur R. basin, 11.06.2004, coll. V. Teslenko; 5 ♂ 7 ♀, Khekhtsirsky Nature Reserve, Beshenaya River, Amur R. basin, 10.06.2018, coll. N. Yavorskaya; Primorsky Krai: 2 ♂ 4 ♀, Avan River, Ussuri R. basin, Amur R. basin, 23.06.1998, coll. V. Teslenko.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFA94BAFF9C3FB5F90A5.taxon	description	Egg. Pear-shaped, triangular cross-section near the posterior ½; anterior ½ quadrangular with distinct cross-shaped ridges near the equator dividing anterior and posterior poles; anterior pole concave (Figs. 90 – 91, 94 – 95). Length 273 ‒ 298 µm, width 175 ‒ 214 µm (n = 5), chorion thickness 2.8 µm. Collar relatively high with irregular longitudinal ridges, base embedded and covered with pits extending to the rim; the rim is narrow, flanged, and wavy (Figs. 92 – 93, 95). Anchor small, biscuit-shaped, and flat, covering only the rim; relatively large, single, globular bodies scattered over the entire anchor surface (Figs. 92 – 93); chorionic surface uniformly and densely covered with numerous small punctations; hexagonal FCIs not visible (Figs. 97 – 98). Eclosion line absent. Micropyles are scattered in groups of 3 or 4 in the subequatorial region (Figs. 90 – 91); orifices slightly elongated and sperm guides poorly visible (Fig. 96).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFA94BAFF9C3FB5F90A5.taxon	distribution	Distribution. East Palaearctic species with a broad geographical distribution in Russia from Siberia (Altai, Sayan Mountains, Baikal Lake Basin, Transbaikalia) to the Far East (Amurskaya Oblast, Jewish Autonomous Region, Khabarovsk Krai, Primorsky Krai). Kazakhstan. Mongolia. China (Huo & Du 2020).	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
03C495232062FFA94BAFF9C3FB5F90A5.taxon	discussion	Remarks. The status of K. nigricauda was discussed in some detail in Huo & Du 2020. Our studies did not reveal any clear differences in the morphological features of Isoperla and Kaszabia eggs, especially since there is overlap with characteristics. It should also be noted that a comparison of the eggs of Kaszabia and Isoperla species with abdominal processes on male terga could not be carried out in full due to the lack of egg descriptions or due to the lack of SEM illustrations. The eggs of K. nigricauda are very similar in shape and chorion structure to the eggs of the Nearctic species Isoperla lenati Szczytko & Kondratieff, 2015. The main difference is the size of the collar; the collar of the K. nigricauda is significantly higher than that of the I. lenati. According to our research, we can conclude that the eggs of Kaszabia are pear-shaped, the anchor is biscuit-shaped, the collar is slightly higher than in the examined Isoperla species, hexagonal follicle cell impressions are not visible, and the chorion is covered uniformly and densely with numerous small punctations.	en	Teslenko, Valentina A. (2025): Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae). Zootaxa 5642 (3): 201-224, DOI: 10.11646/zootaxa.5642.3.1, URL: https://doi.org/10.11646/zootaxa.5642.3.1
