© Zoological Institute, St.Petersburg, 2007 Distinguishing characters of Sternodontus binodulus Jak. and S. similis (Stål) (Heteroptera: Pentatomidae) D.A. Gapon Gapon, D.A. 2007. Distinguishing characters of Sternodontus binodulus Jak. and S. simi- lis (Stål) (Heteroptera: Pentatomidae). Zoosystematica Rossica, 16(1): 138. Though external characters of S. similis and S. binodulus overlap, these species are sepa- rate and clearly differ in the shape of the paramere hypophysis and structure of spermath- eca. D.A. Gapon, Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia. Kulik (1965) synonymized Sternodontus binod- more widely rounded apex. Tubercles just behind ulus Jakovlev, 1893 with S. similis (Stål, 1854), calloused eminences of internal carinae on the but Petrova (1975) considered them separate spe- pronotum are larger in S. binodulus than in S. cies. My data based on the collection of Zoolog- similis. Median carina and apical portions of ex- ical Institute, St. Petersburg, confirm Petrova’s ternal lateral carinae are usually more distinct in opinion. S. binodulus than in S. similis. The paramere hypophysis of S. similis (caudal view!) has a long and thin lateral process; the Acknowledgements external margin of hypophysis between its later- al and anterior processes forms an obtuse angle The collection of Zoological Institute, St. Petersburg, (Fig. 1). In S. binodulus, the lateral process of is supported by Rosnauka for UFC no. 2-2.20. hypophysis is somewhat shorter and wider and References its external margin forms a weakly curved arc (Fig. 2). The variability of external characters of the two Kulik, S.A. 1965. Die Pentatomidenfauna (Heteroptera, Pentatomidae) Ostsibiriens und des Fernen Ostens. species overlaps. Usual states of characters for Acta Faun. Entomol. Mus. Nat. Pragae, 10: 139-161. each species are listed below. Lateral margins of Petrova, V.P. 1975. Shchitniki Zapadnoi Sibiri [Pentato- head of S. similis before eyes converge narrow- moidea of West Siberia]: 1-237. Novosibirsk. (In parabolically and the apex of its head is narrow- Russian). ly rounded, whereas the head of S. binodulus Received 17 May 2007 before eyes is with parallel lateral margins and Figs 1-2. Sternodontus, paramere, caudal view. 1, S. similis; 2, S. binodulus. Scale: 0.25 mm.