70 MISCELLANEOUS STUDIES 



This "pink and green aphid of potato" is distributed throughout 

 California on a large variety of plants. It is recognizable by the long 

 reticulated cornicles and black antennae. When the author first exam- 

 ined specimens of Macrosiphum citrifolii (Ashmead) in Essig's collec- 

 tion he was struck with its resemblance to this species. In fact, after 

 considerable study he could not find any constant differences. This was 

 in 1915 in Berkeley. This past spring (1917) he had the opportunity 

 in Riverside of making some transfer tests with specimens from oxalis. 

 Migrants were placed under muslin bags on sucker growth of orange. 

 It was observed that these settled there readily and produced young, 

 demonstrating that the citrus species is the same as the other. On 

 the strength of this Macrosiphum citrifolii (Ashmead) is listed as a 

 synonym of this species. 



80. Macrosiphum sonchella (Monell) ? 



Monell, U. S. Geol. Geog. Surv., Bull. 5, p. 21, 1879. Siphonophora (orig. 



desc.). 



Clarke, Can. Ent., vol. 35, p. 252, 1903. Nectarophora (list). 

 Davidson, Jour. Econ. Ent., vol. 2, p. 304, 1909 (list). 

 Davidson, Jour. Econ. Ent., vol. 2, p. 380, 1910 (list). 



Records. Sonchus sp. ; Berkeley, Newcastle, and Palo Alto (Clarke); Stan- 

 ford University (Davidson). 



According to Morrison the species listed as this by Davidson is 

 not Macrosiphum sonchella (Monell), although he cannot say what 

 it is. Consequently Clarke probably referred to the same species as 

 did Davidson. As the author has never seen specimens he can make 

 no statement as to its identity, so lists it as it has been heretofore. 



81. Macrosiphum Stanley! Wilson 



Figures 128, 158 



Wilson, Proc. Ent. Soc. Brit. Columbia, January, 1915 (orig. desc.). 

 Eecord. Sambiuxis callicarpa californica; Berkeley, June, 1915. 



From the early part of June, 1915, until the middle of August, 

 this species was very abundant on an elderberry tree in the Botanical 

 Gardens of the University of California. By the latter part of August 

 all specimens had disappeared. Since then the author has never seen 

 the species. J. J. Davis kindly identified these specimens. 



