1918.] BASHAMBAR Das: The Aphididae of Lahore. 265 
marked and their number is often restricted to only two or three, besides the primary 
sensoria on the fifth and sixth article. 3 
They are recognised if one catches them either ovipositing or carrying about an 
egg which is protruding, or by opening up the abdomem under a strong lens or a 
binocular. The ovarian tubes are then seen to contain eggs in place of immature 
embryos. These are packed inside the body right up to the mesothorax ; the num- 
ber is about a dozen in each, but it was found to vary from about 10 to 15 in the 
specimens dissected. 
Abnormalities.—In some cases I have also obtained a few embryos along with the 
usual or a smaller number of eggs. A similar oviparous and viviparous character of 
the females has been noticed by Hunter in Toxoptera graminum (Rond.) (Kansas 
Univ. Bull., No. 2, 1909), but probably if further investigated it would be found to 
be the case in a much larger number of Aphids. Another uncommon variation is a 
stumpy oviparous or viviparous female, very much similar to the alate female in ap- 
pearance, but with rudimentary or no wings. A still more unusual form is met with 
in the “ short-beaked ”’ specimens. These also may be either oviparous or viviparous 
females. The rostrum is so small that it hardly reaches beyond the second coxae, and 
is even less than half the length of that of a normal individual. It is the first joint 
that is reduced’, otherwise the beak is quite complete in all respects. 
The true males have so far escaped my observation, but they may be expected 
to be alate and not very different from the winged females. In other species of 
Dryobius they are said to be slender insects with well-developed genitalia, a sickle- 
shaped penis forming a conspicuous element in the centre. 
The eggs are generally laid in large clusters, each cluster containing several hun- 
dreds ; smaller clusters are also found but frequently the eggs are scattered singly, 
particularly those laid during the latter part of January. Each oviparous female 
contains about a dozen eggs. There are seldom more than this number but fre- 
quently less ; 8 to 10 usually. The eggs are shining black, oval bodies. The laying 
period commences in December and continues in some cases up to the beginning of 
February. The last date of my collection is 25th January. 
The life-history can be summed up briefly. The eggs hatch in March, with the 
flowering of the peach, some days previous to the forming of leaves. ‘These stem- 
mothers give birth to wingless females. There are from 2 to 4 generations of 
the latter before any winged ones are produced. They reproduce at quite an extra- 
ordinary rate. Five apterous viviparous females, colonised on two peach trees in 
December, kept up a steady rate of progress in January, February and the middle of 
March, but only a patch or two of a few hundred specimens was all that resulted 
from them. During March and April, however, there was no limit to their numbers. 
All the larger branches from the bottom upwards were quite covered with them. 
The trees looked as if bathed in oil; the black smothered grass and dry twigs be- 
neath the branches were sticky with the half dried ‘“‘ honey-dew.’’ These twigs 
readily take fire as if immersed in inflammable material. 
The above experiment proved at the same time that the winter can be passed in 
