746 
RHYNCHOTA. 
founded on insufficient characters, and the discrimination of species, 
largely on very variable colour varieties, is extremely difficult. The 
group requires to be properly monographed, 
the genera and species to be founded on 
definite structural characters. Few species 
of Indian aphides are recorded and the 
known species are here summarised ; it is 
certain that there are many more species 
(especially in sub-tropical India), and there 
is a very large field of work in the biology 
of these extremely important and interesting 
insects. 
The wheat aphis (Macrosiphum granarium , Kby.) is found on wheat 
during the cold months, infesting the leaves and ears. As the ears ripen 
Fi g. 519— RHIZOBIOS ,J LT.T U BtE 
Antenna. (I. M. N.) 
Fig. 520— Pemphigus nap^eus. (I. M. N.) 
with the warmer weather, they fly away to the doob grass and feeding 
for a little on this plant, hide away on the surface of the soil. In what 
stage they remain until November has not been ascertained, but they 
reappear then on the wheat and it is probable they pass these months 
in the adult stage. The Cotton Aphis (Aphis gossyjpii, Glov.) is a cos¬ 
mopolitan insect which breeds freely at all seasons of the year if food is 
available. It has been found on cotton and cucurbitaceous plants and 
may have other food-plants. Schizoneura lanigera, Hausm., the so-called 
