2 BULLETIN 276,, U. S. DEPARTMENT OF AGRICULTURE. 



SYNONYMY. 



This aphis seems to have been first authentically described under 

 the name Aphis pisi by Kaltenbach in 1843 (5), 1 although two years 

 previous Boyer de Fonscolombe (3) described a species under the 

 name Aphis onobrychis , which is still doubtfully considered synony- 

 mous with pisi as will be noted later. Kaltenbach placed Schrank's 

 Aphis ulmariae as a synonym of pisi, although this arrangement on 

 the part of that author is not comprehensible, since he was doubtless 

 aware of its priority over pisi. In 1855 Koch (6) redescribed pisi 

 and- placed it in the genus Siphonophora, no mention being made of 

 ulmariae, although in the appendix of this work (p. 328) Kalten- 

 bach 's remarks include the following: 



Siph. gei Koch ist, nach Herrich-Schaffer's richtiger Vermuthung, meine Aphis 

 Pisi Kalt. und Aph. Onobrychis B. de Fonsc. Der altere Schrank'sehe Name Aph. 

 TJImarise verlangt jedoch von alien Dreien das Prioritatsrecht. 



The name pisi was adopted by entomologists almost universally 

 until comparatively recent years when ulmariae was more or less 

 generally accepted. 



In 1909 Dr. N. A. Cholodkovsky (9) published the results of his 

 studies on Siphonophora pisi and related species, definitely settling 

 the identity of pisi, and for the first time pointed out that the 

 Aphis ulmariae of Schrank, which he here placed in the genus 

 Siphonophora, could hardly be the pisi of Kaltenbach. He therefore 

 concluded that three species had heretofore been confused with pisi, 

 namely Macrosiphum pisi, which he had found on garden peas (Pisum 

 sativum), sweet pea (Lathyrus odoratus) and Medicago; M. ulmariae 

 auct., which occurs on meadow-sweet (Spiraea ulmaria) ; and M. 

 caraganae Cholod. on Caragana arborescens, and gives biological and 

 morphological differences to separate the three. Later, in the same 

 year and in the same publication, Dr. A. Mordwilko (10) gives a 

 lengthy treatise on this insect, which he calls Macrosiphum pisi Kalt., 

 and the related species. Eight supposedly distinct species are con- 

 sidered and a table illustrating differences of the following species is 

 given: M. pisi, M. cholodlcovsJcyi, M. portschinsJcyi, M. ononis, J f. yd, 

 and M. urticae. Three species occur on Spiraea ulmaria, namely, the 

 ulmariae of Schrank, which he considers as belonging to the genus 

 Aphis ; M. cholodlcovsJcyi, a name given for the species referred to by 

 Cholodkovsky and other authors discussing a Macrosiphum od Spiraea 

 ulmaria; and M. portschinsJcyi, a new species. The author is evi- 

 dently not settled on the identity of M. ononis Koch, although at 

 the end of the paper he states that "apparently the last species 

 (ononis Koch) must also be reepgnized as distinct." And, finally, 

 M. onobrychis B. de Fonsc. is questionably placed as a synonym of 



1 Numbers (1 to 12) in parentheses refer to tho Bibliography of European Literature, p. 65. 



