226 Memoirs of the Indian Museum. [Vor. VI, 
Literature : — 
Buckton, Brit. Aph., II, p. 110. 
Riley, Insect Life, V, p. 236. 
Gillette, Bull. Color. Exp. Station, No. 133, 1908. 
Fabricius, Koch, Mordwilko, van der Goot and others. 
Distinguishing characters. —Body somewhat linear, green; four tows of white 
powdery spots on back ; very small cornicles ; long cauda ; spur and 3rd article sub- 
equal; the insect crowds closely in an overlapping manner on the leaves, plentifully 
surrounded by white mealy secretion and much appressed to the leaf surface, on 
peaches and Arundo, etc. | 
Systematic.—As noted above this insect has for its host two plants of entirely 
different orders, peach in gardens and Arundo or Phragmites near the water’s edge. 
Arundo is pretty commonly grown as a hedge in Lahore, but the Aphid attacks it only 
on the river-side or along the banks of the Chhota Ravi. 
The specimens developed on peaches occasionally differ in some minor details 
from those on Arundo, but in essential structure they are exactly similar. Fabricius, 
the author of the species, believed them to be distinct from each other, and accord- 
ingly named one Hyalopterus pruni and the other H. arundinis. Koch, Buckton and 
many others held similar views, but it has been definitely established by Riley and 
Mordwilko that the two are the same species with two distinct hosts. When the two 
plants occur in the same locality this fact can be easily observed. 
The specific name pruni, as referring to the more important of the two hosts, is 
more commonly employed than arundinis, though the latter is also in use. 
Life-cycle.—The course of its life-history has been followed in Lahore for more 
than two years and is, in the main, very much the same as what obtains in Europe 
and America. / 
Peaches, specially the young plants, put forth new leaves twice a year, once in 
March and again in September. At both these times thick clusters of the insect may 
be found crowding chiefly on the under side of the leaves. These hatch from eggs and 
from March to early in May several generations of apterous females are produced. 
After this peaches are entirely deserted, although the winged forms that are produced 
even earlier migrate to Arundo or Phragmites. They do not remain even on these 
plants for any length of time. In the summer months they are exceedingly scarce, 
but are in evidence again in September. 
Throughout October alate females come to Avundo and start new colonies. The 
female first makes a white circle of meal, shed from its body, and spreads it evenly 
on the upper surface of the leaf. As long as the brood consists of only a few young, 
the circular form of the white patch is maintained by the mother spinning round upon 
its beak. The waxy secretion adheres tenaciously to the leaf long after all the insects 
have left. Ifa drop of water or honey-dew happens to fall on the Aphids it at once 
becomes a white globule and rolls off without wetting their bodies. During October, 
November and even December apterous and alate females are produced that attack 
both surfaces of the leaves. About the middle of December the alate males and 
