TENTHREDINIDAE 19 



*freyi Lindqvist. N. W. T., Yukon; Circumpolar. 



Pachynematus freyi Lindqvist, 1949. Not. Ent, 28: 81. 9. 



*kirbyi (Dahlbom). Holarctic. Host: Carex. 



ISematus kirbyi Dahlbom, 1835, Clavis Hym. Syst., p. 40. $. 

 ISematus diaphanus Eversman, 1847 (syn. by Benson, 1958. Roy. Ent. 

 Soc. Lond., Handb. Ident. Brit. Ins. 6: 237). 



moerens (Foerster). Host: Gramineae. 



*nevadensis Marlatt. Nev. 



Pachynematus nevadensis Marlatt, 1896. U. S. Dept. Agr. Div. Ent. 

 Tech. Ser. 3: 110. $. 



*obductus (Hartig). Northern U. S., Canada; Holarctic. 



ISematus obductus Hartig, 1837. Fam. Blatt. und Holzwesp., p. 201. 9, $. 

 ISematus palUventris Cresson, 1880 (syn. by Benson, 1962, loc. cit. supra, 

 p. 405). 



palUventris (Cresson). Syn. of obductus (Hartig). 



*parvilabris (Thomson). N. W. T.; prob. Circumpolar. 



ISematus parvilahris Thomson, 1862. Svenska Vetensk. Akad. Ofvers. 



Forh. 19: 638. 9, $. . 

 Taxonomy: Benson, 1962, loc. cit. supra, p. 405. 



*rumiois (Linnaeus). Man., Alaska: Circumboreal. Host: Rumex. 

 Tenthredo rumicis Linnaeus 1758. Syst. Nat., ed. 10, v. 1, p. 559. 



smithae Ross. N. H.; prob. Circumboreal. 



*vagus (Fabricius). Transcontinental in Northern U. S. and Canada; 



Holarctic. Hosts: Carex, Salix. 

 Tenthredo vaga Fabricius, 1781. Spec. Ins., v. 1, p. 415. 

 Pachynematus corticosus MacGillivray, 1901 (syn. by Benson, 1962, loc. 



cit. supra, p. 405). 



Genus CROESUS Leach, p. 42 



Taxonomy: Benson, 1963. Ent. Tidskr. 84: 25. 

 varus (Villaret). Host: Alnus. 



NEMATUS subgenus PTERONIDEA Rohwer, pp. 42-46 



*boreaIis Marlatt. Greenland. 



ISematus borealis Marlatt in Fox, 1892. Acad. Nat. Sci. Phila. Proc. 

 44: 133. $. 



*crassu8 (Fallen). N. W. T. ; Eurasia. Hosts: Betula, Populus, Salix, Rumex. 

 Tenthredo crassa Fallen, 1808. Svenska Vetensk. Akad. Handl. 29: 106. 

 Distribution: Benson, 1962, loc. cit. supra, p. 404. 



fulvicrus Provancher 



ISematus salicis Ashmead, change to Messa salicis. 



*ISematus salicicola Dalla Torre, 1894. Cat. Hym., v. 1, p. 252. N. name 

 for salicis Ashm. 



*jugicoIa Thomson. Man.; N. Europe. Host: Salix sp. 



ISematus jugicola Thomson, 1871. Hym. Scand., v. 1, p. 146. 9. 



mendicus Walsh. Syn. of oligospilus Foerster. 



*oligospilus Foerster. Transcont. in N. Amer.; Holarctic. Host: Salix sp. 

 Nematus oligospilus Foerster, 1854. Naturh. Ver. Preuss. Rheinl. Verb. 



11: 284. 9. 

 ISematus mendicus Walsh, 1866 (syn. by Benson, 1962, loc. cit. supra, 

 p. 405). 



*reticulatus Holmgren. Labrador, N. H., Man., N. W. T., Alaska; Circum- 

 polar. Host : Vaccinium. 



ISematus reticulatus Holmgren, 1883. Ent. Tidskr. 4: 143. 9. 



Pontania glinka Kincaid, 1900 (syn. by Benson, 1962, loc. cit. supra, p. 

 404). 



