Nov. 13,1916 
Rosy Apple Aphis 
325 
rosy aphis the reverse is true, Segment IV being usually the longer. 
Segment III of M. plantaginis is also relatively shorter than is the same 
segment in the rosy apple aphis. 
The synonymy of the rosy apple aphis will thus stand as follows: 
Aphis malifoliae Fitch 
Aphis pyri Boyer of Koch (but not A. pyri Boyer nor A. pyri Koch). 
Aphis sorbi Kaltenbach of recent European and American authors (but not A . sorbt 
Kaltenbach). 
Aphis pyri Boyer of Gillette and Taylor (but not A. pyri Boyer). 
Aphis kochii Schouteden of Theobald (but not A. kochii Schouteden). 
HISTORY AND DISTRIBUTION OF THE SPECIES 
The descriptions given by Koch and Kaltenbach indicate that this 
species was present in Europe at an early date. It now appears to be 
well distributed in the apple-growing regions. In America Fitch’s 
description makes its early presence known. It would seem, however, 
that it was not until about 1900 that the insect assumed the importance 
of a leading pest. The first reports of its occurrence in injurious numbers 
came from the Eastern States, but in the few years following it had been 
observed over a wide area. At present the species occurs over nearly 
all the apple-growing regions of the country, and in some sections it is 
very abundant. In some local areas the insect may be not at all common, 
even though in that general region it is abundant. This seems to be due 
to the comparative scarcity in some places of its secondary host, and in 
areas where the insect assumes considerable importance plantain is 
usually found in great abundance. Although the species occurs abun¬ 
dantly in some of the Northern States, it does not seem as yet to have 
penetrated very far into Canada. It occurs in Quebec, Ontario, and 
British Columbia, but nowhere in Canada does it seem to have assumed 
such importance as in some sections of this country. 
METHODS OF STUDY 
Experiments. —The experiments on which this paper is based were 
conducted along much the same line as recorded by the writers (n) for 
the green apple aphis. Eggs were allowed to hatch and the stem 
mothers and their offspring to grow on young seedlings in pots. The 
same methods of transfer adopted for the green aphis were employed 
with this species. As soon as spring migrants were produced, these 
were transferred to rib-grass plants grown in pots, and covered with 
lantern globes. In this manner the species was grown throughout the 
summer, and in the fall the fall migrants and males were returned to the 
apple. All insects possible were reared to maturity in order that the 
percentage of winged forms occurring throughout the summer might be 
ascertained. Winged forms during the summer proved to be rare and 
this simplified considerably the handling of the insects, since it reduced 
