720 Rospert MATHESON 
present at least. However, Theobald’s description undoubtedly refers to 
Aphis sorbt Kalt., not Aphis kochii Schouteden (Aphis pyri Koch). 
The following table presents what the writer considers the synonymy 
of this species: 
Aphis sorbi Kaltenbach 
Aphis pyri Boyer of Koch, not Aphis pyri Boyer 
Aphis malifoliae Fitch 
Aphis kochii Schouteden of Theobald, not Aphis kochii Schouteden 
Aphis pyri Boyer of Gillette and Taylor, not Aphis pyri Boyer 
HISTORICAL 
The rosy apple aphis is a European species which was introduced into 
America at an early date; when or where this introduction took place 
cannot be determined because of the confusion in literature of the three 
species now known to be common on apple. Very little is known of the 
history of this species in America, and because of the meagerness of ref- 
erences and descriptions it seems impossible to do more than summarize 
the situation. 
Fitch (1855) first described what is undoubtedly the winged fall 
migrant of this species under the name Aphis malifoliae. The material 
on which his description was based was collected on apple leaves in Mercer 
County, Illinois, on October 4, 1854. Thomas (1879) considers Fitch’s 
species as valid, and presents a description copied largely from the original. 
However, he adds his own observations and concludes that this species 
is aS common and widespread in southern Illinois as is Aphis mali Fabr. 
(this includes Aphis pomi De G. and Aphis avenae Fabr.). The next 
positive reference to this species is by Comstock (1894). His reference 
to Aphis sorbi is given with a question mark. However, thru the kindness 
of J. J. Davis, who has recently examined the Monell collection, the 
writer can state that the species to which Comstock referred is Aphis 
sorbi Kalt. Mr. Davis found specimens of this species sent by M. V. 
Slingerland in September, 1893, to Monell, and Comstock’s reference is 
certainly to this material. 
Lugger (1900) refers to this species and presents figures illustrating 
the insect and its work, but does not state that he found it in Minnesota. 
The first real work on the bionomics of this species was by Sanderson 
(1901 and 1902). Since that time various short articles have appeared 
in widely separated parts of the United States, the only detailed accounts 
