THE NORTH AMERICAN ICHNEUMON-FLIES OF THE 



TRIBES lABENINI, RHYSSINI, XORIDINI, ODONTO- 



MERINI, AND PHYTODIETINI. 



By S. A. RoHWER. 



Of the Bureau of Entomology, United States Department of Agriculture. 



This paper, which is a contribution from the Branch of Forest 

 Insects, Bureau of Entomology, is based on the collections in the 

 United States National Museum but the types which are in other Ameri- 

 can collections have been examined and notes on them have been used 

 in the discussion of the species. The types of all new species are in 

 the National Museum. In the tribe Labenini notes on all the material 

 in the National collection have been included but in the other groups 

 the notes and keys mclude only the species found north of Mexico. 



The definition and limits of the tribes used in this paper is the same 

 as those proposed by Cushman and Rohwer.' All of the drawings 

 were prepared, under the writer's supervision, by Miss Mary Carmody, 

 formerly of the Branch of Forest Insects, Bureau of Entomology. 



Tribe LABENINI Ashmead. 



Labenini Ashmead, Proc. U. S. Nat. Mus., vol. 23, 1900, p. 48, (part). 

 Labenini Schmiedeknecht, Gen. Insect., fasc. 62, 1907, p. 94, (part). 

 Labenini Cushman and Rohwer, Proc. U. S. Nat. Mus., vol. 57, 1920, p. 394. 



Ashmead was the first writer to propose a tribe for these American 

 insects, but the tribe as originally defined by him included also the 

 Ophionine genus Nonnus Cresson. Schmiedeknecht followed Ash- 

 mead in including Nonnus in the Labenini but this is undoubtedly 

 due to the fact that he did not know the genus (under that name) 

 because he had redescribed it, as pointed out by Viereck,^ under the 

 name OpMonocryptus. 



The tribe Labenini is very distinct, yet recalls through Labena 

 Cresson the Rhyssini and through Orotea Ci'esson there is a suggested 

 affinity to some Ophioninae. The larvae are externally parasitic on 

 larvae which live within woody tissue. Labena is parasitic on wood- 

 boring Coleoptera, while Grotea is parasitic on bees and wasps and at 

 least in some instances is phytophagous through part of its life. 



1 Proc. U. S. Nat. Mus., vol. 57, 1920, p. 379. « Idem, vol. 46, 1913, p. 377. 



Proceedings U. S. National Museum, Vol. 57— No. 2317. 



405 



