No. 2317. FIVE TRIBES OF WHNEUMONINAE—ROHWER. 425 



the second Provancher collection in the Public Museum of Quebec and 

 bears yellow label 1260. Discussion based on the tyjjes, homotypes 

 and specimens from the localities listed below. 



Specimens of males and females reared from the same piece of maple 

 limb included males which could not be distinguished from the 

 type of nitida and females which could not be distinguished from 

 the type of canadensis; so there can be no doubt that the above 

 synonym}^ is correct. This species is very close to the European 

 curvi'pes (Gravenhorst) and other than the unsatisfactory color char- 

 acters given in the above key no differences could be found. It seems 

 to the writer, that it is better to retain Cresson's name for the Amer- 

 ican form until there is more evidence that it is the same as the 

 European species. Merrill's^ conception of this species is entirely 

 wrong, as is abundantly proven by the types and the descriptions 

 The abdomen is black. 



Distribution. — "Virginia, Dr. T. B. Wilson" (type-locality for 

 nitida) ''Quebec, Couper" (type locality for canadensis); "Cap 

 Rouge" (type-locality for clavata); Pennslyvania ; Clemen ton, New 

 Jersey; Washington, District of Columbia (van Horn); Plummer's 

 Island, Maryland (Barber, Middleton, Rohwer); Columbia, South 

 Carolma (G. F. Atkins); Akron, Ohio; Detroit, Michigan. 



Host. — ^According to rearings by van Horn, Middleton and Rohwer 

 of the branch of Forest Insects of the Bureau of Entomology this is a 

 common parasite of the larva of Xiphydria maculata Say. 



Genus MEGARHYSSA Ashmead. 



Thalessa Holmgren, Ofvers. Svensk. Vet. Akad. Forh., vol. 16, 1859, p. 122 (pre- 

 occupied by Adams in 1853). Genotype. — (Ichneumon) Megarhyssa superhua 

 (Schrank). Through eynonymy. 



Megarhyssa AssuE AD, Can. Ent., vol. 32, 1900, p. 368. 



This generic group was fii'st recognized by Holmgren, but unfortu- 

 nately in naming it he chose a name which had already been used, so it 

 was necessary to rename it and this was done by Ashmead in 1900. 

 Neither Schmiedeknecht nor Morley have thought it necessary to use 

 Ashmead's name, although they may have been misled by the way 

 Dalla Torre gives the references. 



^ The Nearctic species of this genus are easily recognized by the size, 

 long ovipositor, and color. The Oriental species are apparently not 

 as easily recognized by superficial characters, as there seems to be 

 some confusion about the genus Lytarmes Cameron, which has never 

 been satisfactorily characterized. 



All of the species which have been reared are parasitic on the larvae 

 of horntails and all but one of them seem to confine their attacks to 

 species of the genus Tremex. 



1 Trans. Amer. Ent. Soc, vol. 41, 1915, p. 137. 



