DISCOVERY OF THE WHEAT STEM SAWFLY (CEPHUS CZNCTUS NORTON) (: ) IN ASIA, WITH THE PROPOSAL OF A NEW SYNONYMY MICHAEL A. IVIE Department of Entomology, Montana State University, Bozeman, Montana 59717, USA and ALEXEYG. ZINOVJEV Zoological Institute, Russian Academy of Science, St. Petersburg, 199034 Russia The Canadian Entomologist 128: 347-348 (1996) While conducting research on the geographic origin of the wheat stem sawfly ( Norton), we compared North American specimens to specimens of Eurasian Cephus spp., and discovered that specimens currently placed as C. hyalinatus Konow from Siberia are conspecific with the North American species. Given the pest status of the North American populations, which attack wheat and other cereals in the upper Great Plains (Weiss and Morrill1992), this discovery has important implications for the management of the species. Discussion of these implications will be provided elsewhere (Ivie 1996). Cephus cinctus was described from Colorado (Norton 1872), and is known from the Pacific Coast states and British Columbia to Ontario and Georgia (Ivie 1996). The male holotype is in the Academy of Natural Sciences, Philadelphia, and agrees with the interpretation of the species by all recent authors (D.R. Smith, in litt.). Cephus hyalinatus was described from Irkutsk (Konow 1897). It is recorded from Siberia (Altai, Yeniseisk, Irkutsk, Lower Amur, and Kamchatka) (Gussakovskij 1935; Verzhutskii 1966,1974,1981; Stroganova 1982), Hokkaido, and Sakhalin (Takeuchi 1938). Konow's female holotype is in the Deutsche Entomologische Institut (DEI), Eberswalde (Oehlke and Wudownz 1984). For the identity of this species, we accept the interpretation of Muche (1981), who had access to this type. Specimens of C. hyalinatus in the Zoological Institute, St. Petersburg, and Moscow State University were examined from several Siberian locations: Irkutsk, Khabarovsk, Teletskoie Ozero [Lake] (Altai), Minusinsk area (Khakasskaya Oblast), Amur [interpreted to mean lower Amur River Region, following Gussakovskij (1936)], and Kamchatka. This material included specimens determined by Gussakovskij and Zhelochovtsev. Several hundred specimens of C. cinctus in the Montana Entomology Collection were available for comparison. No world revision of the genus has been published, and only Muche (198 1) treats all the described species, although he was mainly limited to material in the DEI collection at Eberswalde, supplemented by some from Humboldt-Universitat, Berlin. Nearctic and Palearctic species were treated in separate keys, and the Nearctic key is a shortened translation of Middlekauff's (1969) key. However, Montana specimens of C. cinctus run to C. hyalinatus in Muche's (1981) key to Eurasian Cephus, as well as in Takeuchi's (1938) key to Cephus species of the former Japanese Empire. Specimens of C. hyalinatus run to C. cinctus in keys to North American species (e.g. Middlekauff 1969). In addition to the gross external comparison of the specimens mentioned above, four specimens from Khabarovsk and one from the Amur region were compared in great detail with specimens from Montana and North Dakota by MAI, and over 50 specimens from Russian Asia were compared with several specimens from Canada and Montana by AGZ. Details of coloration, venation, male genitalia, and the female saw of the Siberian specimens were examined, and found to be within the range of variation of the North American specimens. The setation of the male seventh stemum in both Siberian and Amurian specimens we have examined has an extensive area of consistently strong setation extending very nearly to the anterior margin, and without a distinct "edge". Alternatively, the Nearctic populations are extremely variable in this character, with specimens ranging from similar to the Palearctic specimens to completely glabrous. No "edge" can be seen in either of these extremes. The most common situation in the Nearctic is for the male seventh stemum to have strong setation on the posterior portion and this area to be margined anteriorly by a distinct "edge". This variability does not exclude the conspecificity of these populations, and may relate to the expected effects of a small founding population (Benson 1962). Thus, C. cinctus Norton 1872 is proposed to be the senior synonym of C. hyalinatus Konow 1897, NEW SYNONYMY. Although this preliminary report of findings was necessary because of the importance of this species to wheat production in the Great Plains of Canada and the United States (Ivie 1996), it is far from the last word on this subject. The taxonomy of Cephus is in such a poor state that a revision is 348 THE CANADIAN E?4TOMOLOGIST Mar~h/April1996 badly needed to understand species limits, including those of C. cinctus. In addition to the need for investigations of genetic population structure to test our hypothesis, there is considerable further uncertainty as to the full extent of synonymy in this species. Cephus cinctus seems rather similar structurally to several other "species". At the minimum, further research will very likely support Gussakovskij's (1935) suggestion that C. carntschatcalis Enslin is a conspecific, darker morph of C. cinctus (as C.hyalinatus). Cephus cinctus runs to the Crimean C.zahaikevitschi Ermolenko (known only from a unique female) in Zhelochovtsev's (1988) key to the species of the European USSR, indicating C. zahaikevitschi may also belong to this group. That key did not include the Asian C. hyalinatus, and we have seen no specimens referable to C. zahaikevitschi. Cephus zahaikevitschi was included in the group of species separated as the now-synonymized subgenus Pseudocephus Dovnar-Zapolsij (Zhelochovtsev and Zinovjev 1996), so perhaps all species assigned there by various authors should be suspected as possible synonyms. Lastly, at least some specimens of the type series of C. tshettui Stroganova belong to C. cinctus in the new sense (Zhelochovtsev and Zinovjev 1996). We hope to undertake a revision of this genus in the near future, and address these problems therein.

The Montana Wheat and Barley Committee and the Montana Agricultural Experiment Station (MAES) funded museum visits by MA1 to Washington, Moscow, Leningrad (now St. Petersburg), and Paris to examine collections. The support of Department Heads J. Wayne Brewer and Greg Johnson, and former MAES Director James Welch, were critical to this study. The travel of AGZ to the United States was made possible through L.S. Kimsey, University of California, Davis, and the International Society of Hymenopterists. We thank A.V. Antropov (Moscow State University), H. Goulet (Agricul- ture Canada, Ottawa), and D.R. Smith (USDA-SEL, Washington, DC) for access to the collections in their care. David Smith also freely provided access to his extensive notes on sawfly taxonomy, and information on the type specimen of C. cinctus. For reviews of the manuscript, we thank D.A. Pollock, R.S. Miller, H. Goulet, and D.R. Smith. This is contribution J-3035 of the Montana Agricultural Experiment Station.

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