PROCEEDINGS OF THE 



ENTOMOLOGICAL SOCIETY OF WASHINGTON 



VOL. 20 NOVEMBER, 1918 No. 8 



NOTES ON, AND DESCRIPTIONS OF SAWFLIES BELONGING TO 

 THE TENTHREDINID TRIBE HEMICHROINI (HYM.) 



BY S. A. ROHWER, 



Specialist in Forest Hymenopter a, Bureau of Entomology, Washington, D. C. 



The following paper is based on the collections of the U. S. Na- 

 tional Museum, but it contains also some notes on the types of 

 species in other collections. In presenting these descriptions of 

 new species it has been considered advisable to give generic and 

 specific keys; and to add a list of the species known from the 

 Neartic region. The writer wishes to express his indebtedness to 

 Miss Margaret M. Fagan, for assistance in preparing the list of 

 the species, and compiling references. 



TRIBE HEMICHROINI ROHWER. 



Hemichroini Rohwer, Proc. Ent, Soc. Wash., vol. 13, 1911, p. 225; Rohwer, 



Proc. U. S. Nat, Mus., vol. 43, 1912, p. 238. 



Hoplocampinae Rohwer, Proc. Ent, Soc. Wash. vol. 13, 1911, p. 220, 225: 

 MacGillivray, Proc. U. S. Nat. Mus., vol. 29, 1906, MacGillivray, Bull. 

 22, Conn. Geol. Nat. Hist. Survey, 1917, p. 105. 



iliinae MacGillivray, Proc. U. S. Nat. Mus., vol. 29, 1906, p. 635 (part); 

 Bull. 22, Conn. Geol. Nat. Hist, Survey, 1917, p. 108 (part). 



;i Enslin, Deutsch, Ent, Zeitschr., 1914, Beiheft. p. 244 (part). 

 ?s Konow, Gen. Ins., fasc. 29, 1905, p. 71 (part). 



Xi'/natini Enslin, Deutsch. Ent. Zeitschr., 1915, Beiheft, p. 311 (part). 

 Nematides Konow, Gen. Ins., fasc. 29, 1905, p. 44 (part). 



Other authors have placed undue stress on the value of the 

 interradius and thus placed the genera here grouped together in 

 the tribe Hemichroini in different subfamilies. According to 

 the writer's opinion the presence or absence of the interradius, in 

 all those groups in which the prepectus is present, can only 1><- 

 used as a generic character. MacClillivray has laid consideraM" 

 stress on the formation of the two anal cells, and while this char- 

 acter is of great importance and is used by the writer to sep:ir;ite 

 the tribe Hemichroini from the tribe Xeniatini. it is not of 



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