464 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iis 



Type locality: Glendale, Calif., collected in 1914 by T. D. Urbahns, 

 Webster no. 11214. 



Distribution: United States: Northern United States from coast 

 to coast. Canada: Alberta, Quebec. 



Host: Agropyron repens (Linneaiis) (Cornell University collection. 

 Host not stated). Phytophaga destructor (Say), (Gahan, 1933). 

 Harmolita tritici (Fitch) (Gahan, 1933). Elymus canadensis Linneaus 

 (Gahan, 1933, host not stated). Harmolita atlantica Philhps and 

 Emory (specimens in U.S. National Museum collection). Elymus 

 triticoides, E. condensatus (specimens in U.S. National Museum 

 collection). Harmolita elymophage PhiUips and Emory (Peck, 1951 

 in Muesebeck et al, U.S. Dept. Agric. Monogr., no. 2). Scolytus 

 rugulosus Ratzeburg (Peck, 1951 in Muesebeck et al, U.S. Dept. 

 Agric. Monogr., no. 2). Galls on Sitilias grandiflora (Brandhorst, 

 19^43). 



Remarks: See Bugbee (1956) for notes on synonymy of this species. 

 The most Hkely hosts of E. pachyneuron appear to be species of 

 Harmolita on Elymus species. The record from Scolytus rugulosus 

 (Ratzeburg) seems doubtful. The reference to Phytophaga destructor 

 (Say), although doubtful, might be possible, since Phillips (1917) 

 showed that E. pater = (E. pachyneuron) may be parasitic on Harmolita 

 larvae in the early stages of its larval development but can finish its 

 late larval growth as a plant feeder. In its earlier stages, it might 

 destroy Hessian fly larvae as well as Harmolita. 



In the collections of the U.S. National Museum, Department of 

 Agriculture, Ottawa, Canada and Cornell University are numerous 

 long series of E. pachyneuron. In the majority of cases, the host plant 

 is cited as a species of Elymus, but the insect host was determined in 

 one or two cases only. In the Cornell University collection is a long 

 series from Quackgrass (Agropyron repens) but without any insect host 

 designation. Harmolita species do occur in this grass and therefore 

 could serve as hosts. 



This is a variable species as pointed out in the article by Bugbee 

 (loc. cit.). Leg color which was used to separate E. pachyneuron, 

 E. pater, and E. phoebus proved unreHable, and since the three species 

 were alike in aU other characteristics, the latter two were placed in 

 synonymy with E. pachyneuron. 



The wide postmarginal vein in relation to the Unear marginal vein, 

 the clavate antennae, the weakly developed female genitalia with the 

 wide dorsal valves and stylet arch in a horizontal plane, added to the 

 characteristics mentioned in the key, will help to distinguish this 

 species. 



