210 - Memoirs of the Indian Museum. | [Moz avails 
under natural conditions. The few individuals that mature at once fly off to more 
succulent plants when the ones on which they have been feeding show signs of a decreas- 
ing flow of sap. To obtain alate specimens one has often to artificially weaken the 
plants in confinement, in order to accelerate the production of pupae. Taking two 
typical plants of summer and winter crops, as wheat and maize, the life-history would 
ordinarily be alternating on them. Avena, I believe, suffers most from its attack, for 
in the rolled-up young leaves thousands would frequently be found weakening and 
disfiguring the plants. This position, referred to already above, is very characteristic, 
and the insect must be responsible for a considerable amount of loss, by retarding 
growth and not allowing the leaves to open for a long time. 
On maize it attacks the male inflorescence from September to N Deer. when it 
migrates to Avena and wheat, which are just sprouting. 
Experiments.—In order to determine the course of its life-history in the Punjab, 
a number of individuals were colonised on Cynodon dactylon (common dub-grass) 
grown in small flower pots, under muslin-topped lamp chimneys. They were kept in 
the laboratory, the pots being irrigated from below. Some colonies were left in the 
Botanical Gardens under field conditions, at the place where they were first noticed. 
The experiments were started early in October, 1913. Throughout the winter, that 
is up to the middle of January, viviparous reproduction went on, and alate or apterous 
individuals were formed more or less promiscuously. 
The details as to the number of moults, the age at which reproduction com- 
menced and stopped, the days an individual lived, etc., were much the same as those 
given by J. J. Davis, and need not be repeated here. 
White-banded apterous viviparous female.—Early in February a few apterous vivi- 
parous females were observed that were conspicuous among the colonies in the labo- 
ratory as well as in the field. Each carried several thick white bands or stripes of 
mealy powder, one to each body segment. Sometimes the band was discontinuous in 
the middle, and one or two elliptic spots were in some cases noticed situated latero- 
dorsally on the immature females, but the full number developed only on adult speci- 
mens. These were slightly larger and much darker than ordinary females; the 
cornicles were distinctly narrowed at the tip. 
Measurements of one are given below :— 
Antennal proportions :— 
III. Lv: V: VI 
12 9 85 Dar 
Lensths.. 0:20 0'15 0'I4 0'0I+0'25 mm. 
Body = 2 50 OL tanta 
Antennae 227000. 1m. 
Cornicle 0.20, 1, 
Cauda oh Os aa 
We are not in a position to say positively what is the significance of this ‘‘ band- 
ing’’; it has been noticed in A. rumicis, and I have also noted it in ‘‘ malviform ” 
