Studies On Sinacroneuria Yang & Yang (Plecoptera: Perlidae) With Description Of New Species From China And Vietnam Author Stark, Bill P. Box 4045, Department of Biology, Mississippi College, Clinton, Mississippi, U. S. A. 39058 E-mail: stark @ mc. edu stark@mc.edu Author Sivec, Ignac Slovenian Museum of Natural History, Prešernova 20, P. O. Box 290, SLO- 1001 Ljubljana, Slovenia E-mail: isivec @ pms-lj. si isivec@pms-lj.si text Illiesia 2008 4 15 150 153 journal article http://doi.org/10.5281/zenodo.4754757 ace285f1-f04e-45d4-b04f-14108c117e2c 1854-0392 4754757 Sinacroneuria biocellata n. sp. ( Figs. 1-4 ) Material studied. Holotype ♂ from Vietnam , Lao Cai , Sapa , large waterfall on Sapa to Lai Chau road , UV light, 8 May 1995 , D. Currie , B. Hubley , J. Swann , ROM 956022 ( ROM ) Adult habitus. Biocellate. Head with large dark brown area covering ocelli and extending to M-line ( Fig. 1 ); lappets and saggitate mark forward of M-line pale brown. Pronotum pale brown with scattered obscure rugosities on disk; margins and median suture dark brown. Wing membrane transparent, veins pale brown. Femora pale but slightly darker along dorsal edge; tibiae brown. Segments on basal half of antennal flagellum dark brown but apical segments pale. 1 3 Male. Forewing length 16.5 mm . Tergum 9 with sparse mesal patch of sensilla basiconica narrowly divided along midline; tergum 10 with sensilla basiconica patches widely separated and tergum almost divided by membrane ( Fig. 2 ). Paraproct tips small, acute and darkly sclerotized. Cerci short, consisting of about 14 segments. Hammer present on sternum 9. Y-stem of aedeagal sclerite short ( Fig. 3 ); arms wide basally and about 2.5 times long as stem; ventral surface of aedeagus armed with a slender, median sclerite, sparsely covered with small spines ( Fig. 4 ). 4 Figs. 1-4. Sinacroneuria biocellata . 1. Head and pronotum, 2. Male terminalia, 3. Aedeagus, dorsal aspect, 4. Aedeagus, lateral aspect. Female. Unknown. Larva. Unknown. Etymology. The species name refers to the presence of only two ocelli on this species. Diagnosis. Sinacroneuria biocellata adults are distinguished from those of congeners by the presence of only two ocelli. Males appear to have more widely separated sensilla patches on tergum 10 and those on tergum 9 are less abundant and form a more-or-less united patch. Additionally the aedeagal sclerite Y-stem is relatively shorter than is shown by Yang & Yang (1995) for S. orientalis . Yang & Yang (1995) also show the 10 th tergum of the male to be completely divided by membrane, and this species has the membrane strip incomplete.