BLACK GRAIK-STEM SAWFLY. 6 



ent points in Maryland and Pennsylvania. The fact that Trachelus 

 tcibidus was thus known to occur in the region of the infestation and 

 that it was the only species of Cephidae known to occur there which 

 would be likely to have the habit attributed to this one, at once es- 

 tablished a strong probability that it was the species concerned. 

 This suspicion was confirmed when Messrs. W. R. McConnell and 

 P. R. Myers, who had been engaged for several years in investigating 

 the insect enemies of wheat and other cereals for the Bureau of Ento- 

 mology in Maryland and Pennsylvania, turned over to the writer all 

 of the sawfly material which they had secured from that region. 

 This material all proved to be Trachelus tabidus and included sev- 

 eral specimens which had actually been reared from wheat stubble 

 in breeding cages, as well as numerous specimens collected by sweep- 

 ing wheat. The reared material left little doubt as to the identity of 

 the depredator in question. Reference to the European literature, 

 especially that by a number of the more recent Russian entomologists, 

 regarding Trachelus tabidus, cleared up whatever lingering doubts 

 might still have existed. 



The manner in which this insect became established in America is 

 unknown and probably will remain a mystery. Any surmise as to 

 the probable manner of introduction would be valueless and since it 

 could have no effect upon the fact that it probably has come to remain, 

 is omitted. 



COMMON NAME OF THE SPECIES. 



In Russian literature this species is referred to as the black sawyer 

 or black sawfly because of its nearly uniform black color. The writer 

 has ventured to modify this name to some extent by calling it the 

 black grain-stem sawfly. This name is descriptive of the insect as 

 well as of its habit and at the same time minimizes the possibility of 

 confusion with other black species of sawfly. 



DISTRIBUTION. 



OLD-WORLD DISTRIBUTION. 



Andre (33) records the species as occurring in England, France, 

 Sweden, Spain, Germany, Italy, Algeria, and Syria. Cameron (35) 

 in his "Monograph of the British Phytophagous Hymenoptera " 

 gives practically the same distribution, omitting France. Konow 

 (42) in Genera Insectorum cites middle and southern Europe, Algeria, 

 and Asia Minor. Several writers, including Shtchegolev (49) , Kurd- 

 jumov (48), Uvarov (50, 54), Zolotarevsky (53), and Borodin (52), 

 have recorded it more recently from central and southern Russia, 

 while Kulagin (47) states that Oephus pygmaeus and Trachelus 

 tabidus have been recorded from 26 different governments of Russia. 



