INSECUTOR INSCITI^ MENSTRUUS 17 



Horse, Yukon Territory, June 26 and July 17, 1919 (H. G. 

 Dyar). 



This species is allied to curriei and campestris, of the size 

 of the latter, but differing in the male genitalia, which have no 

 stout spine on the margin of the basal lobe of the side piece. 

 It occurred in pine country from the White Horse Rapids to 

 the Tahkeena River, about 25 miles, but was not met with 

 elsewhere, except a single female at Skagway, which may 

 have been carried down on the train. 



The males swarm after sunset in little groups close to one 

 side of the tops of small pines (resembling lodgepole pine). 



The larvae were not observed, all having emerged at the date 

 of my visit. 



This may not be specifically distinct from campestris. While 

 male campestris from Regina and Carnduflf, Saskatchewan, 

 have the larger marginal spine on the basal lobe of the side 

 piece as indicated above, a male from Salt Lake County, Utah, 

 April 30, 1914 (C. T. Vorhies), does not show it distinctly, 

 while a male from Oxbow, Saskatchewan, June 19, 1907 

 (F. Knab), shows the enlarged spine on one side but not on 

 the other. Several of the marginal spines are enlarged in all 

 the specimens, and whether there is a central one dififerentiated 

 may prove an evanescent character. 



The habits of campestris are undescribed, and the larva is 

 unknown, and therefore I hold callithotrys apart for the 

 present. 



The species seems addicted to pine country instead of the 

 open prairie, as with curriei. Its distribution is peculiar and 

 restricted. The swarming habits are markedly different from 

 those of curriei. Specimens recorded by me from Charlton 

 Island in James Bay (Ins. Ins. Mens., vii, 38, 1919) are un- 

 doubtedly callithotrys or campestris. No males were obtained 

 from this locality. 



Total, 816 specimens : White Horse, Yukon Territory, Jime 

 26- July 18, 1919; Tahkeena River, Yukon Territory, July ]9. 

 1919 ; Skagway, Alaska, June 25, 1919. 



