FOREWORD. 
The studies on plant-lice embodied in this paper were chiefly carried out at 
Lahore, in the Government College Biological Laboratory, under the direction of 
Lt.-Col. J. Stephenson, D.Sc., Principal and Professor of Biology. 
In order to consult reference literature and to examine any previous Aphid 
material, opportunities were taken for spending some time in the Entomological sec- 
tions of the Agricultural Research Institute at Pusa (Behar) and the Indian Museum 
in Caleutta (Bengal). Shorter visits were paid to similar institutions at Lyallpore 
(Punjab), Dehra Dun (United Provinces) and Poona (Bombay). 
Descriptive accounts and life-histories, so far as known, of forty species, new 
and old, belonging to eighteen different genera, have been dealt with. Plates and 
Camera lucida drawings accompany all, as well as the characters of genera and identi- 
fication tables where necessary. A host-plant index has also been prepared and is 
given at the end. 
With the object of facilitating further work on Aphids in India, an attempt is 
herein made to present in one place all information of this nature that exists con- 
cerning these insects in this country. Lines for additional investigations, therefore, 
and special points requiring more extended observation are indicated throughout, 
Mest of the theoretical considerations, as well as the measures for controlling such 
as are pests, have not been touched upon at all. 
The relation of plant-lice to their environment, and in particular to their insect 
friends and enemies in India, could merely be given in some cases ; their detailed 
account has been reserved for an independent treatment. 
For the rest, taking into account the very scanty earlier knowledge on Oriental 
Aphids, it may be hoped that what is contained in the following pages would be of 
interest either as new, or recorded for the first time from India. 
It would be of use to note, in this connection, that Lahore is situated in 31° 35’ 
N. and 74° 20” E.; its height above sea level is 732 feet. The hottest months are May 
and June with a mean maximum temperature of about 106°; the actual highest may 
go up to 120°. The mean minimum for the cold months of December and January is 
nearly 40°; the actual lowest has never gone below 29°. The amount of rainfall 
ranges between eight and twenty-five inches, but is chiefly confined to the ‘‘rainy 
season’ in July and August. 
The time for shedding leaves differs in most of the deciduous plants, so that in 
the plains we do not have a “winter” preceded by an “autumn” or ‘‘ Fall,” when 
all the plants are devoid of foliage. Wheat and several other cereals are ‘‘ winter 
crops’’ ; when harvested in April no “ volunteer wheat’’ remains in the fields. 
