Isoperla pseudornata Zhiltzova, 1988

Teslenko, Valentina A., 2025, Eggs of twelve Siberian and Far Eastern Isoperlinae (Plecoptera: Perlodidae), Zootaxa 5642 (3), pp. 201-224 : 218

Isoperla pseudornata Zhiltzova, 1988

Figs. 81–89

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♀ 3L, 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♀ 1L, 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 .

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 ).

Distribution. East Asian species with limited distribution in the south of the Russian Far East, Jewish Autonomous Region, Khabarovsk Krai, and Primorsky Krai.

Figures

FIGURES 81–89. Isoperla pseudornata Zhiltzova, 1988. Russia, Far East, Primorsky Krai, Ryazanovka River, near the hunting grounds. Egg. 81. Habitus, with anchor and micropylar row, lateral. 82. Habitus, with collar, lateral. 83. Anchor with globular bodies, lateral. 84. Collar with irregular and raised longitudinal ridges and flanged rim. 85. Posterior pole with shallow embedded anchor, view from above. 86. Anterior pole with slightly concave apex, view from above. 87. Posterior pole, with collar, smooth shoulder surrounded with a row of pits, view from above. 88. Chorion structure, lateral. 89. Micropylar row, orifices located on the top of FCI ridges, sperm guides are short and thickened.