THE CANADIAN ENTOMOLOGIST 47 



Pupa. 



General colour pale green, the head thorax and distal half of 

 abdomen appearing to be scantily pulverulent, giving these parts 

 a slight whitish tint; the rather prominent median longitudinal 

 dorsal line of a darker green colour than that of the body and ex- 

 tending the entire length of the abdomen and thorax. Segments I 

 and II of the antenna whitish green; the remaining segments pale, 

 with a slight brownish tint, excepting the extreme tip of III and 

 IV, the end of V, and all of VI, which portions are blackish. Eyes 

 red. Legs with femora pale green, with an apparently light pul- 

 verulence; tibiae of a very faint brownish tint, the tips dark brown; 

 tarsi black. Basal one-half or one-third of cornicle pale green, 

 the remainder with a pale brownish tint, and the tip darker. Cauda 

 concolorous with abdomen. 



Oviparous female. 



In a lot of live specimens received from Mr. G. I. Reeves, 

 November 20, 1911 (collected on alfalfa at Salt Lake City, Utah, 

 November 15, 1911), two wingless females with typical oviparous 

 female characters, namely, swollen hind tibiae bearing numerous 

 sensoria, were found, but upon closer examination one of these 

 was found to be filled with young and no eggs, while the others 

 appeared to contain no eggs and the eye spots of a single young 

 within the body were to be seen. Later on specimens from this 

 lot were reared which proved to be both physiologically and morpho- 

 logically oviparous, but specimens were not preserved. These 

 females differed from the usual wingless viviparous females by 

 bearing 75 or more small, rather inconspicuous sensoria on the hind 

 tibia and by having 7 to 11 circular sensoria on segment III of 

 antenna. 



The eggs are deposited on the foliage of alfalfa and from all 

 observations the aphidid occurs on alfalfa, which is evidently 

 its prime host, the year round. 



This large green Macrosiphum, which so closely resembles the 

 destructive pea aphis {Macrosiphum destructor Johns.) was first 

 received from Mr. Cecil W. Creel of this bureau, who found it very 

 abundant on alfalfa at Fernley and Lovelock, Nev., May 20 and 

 22, 1911. From reports this species is already a more or less 

 troublesome pest on alfalfa in Utah and Nevada, and may become 



