100 Memoirs of the Indian Museum. Wor. Vag 
Among Aphidinae the number of eggs normally does not exceed a few and very 
often it is only one. The European Aphis brassicae, Linn. (according to Harrick in 
the Jour. Econ. Entomology, vol. IV, p. 219, 1911) lays on an average about four eggs- 
When freshly laid the colour of the eggs is yellowish, mottled on the surface with 
greenish dots. The micropylar side is narrower than the other and constricted into a 
greenish cap. As usual the eggs in a few days turn jet black and remain so till ready 
for hatching some time in the spring. 
The males are likely to be alate, but none have been secured. They may be 
emerging a little earlier in the season, about the beginning of November. 
Life-history.—This is by far the commonest Aphid in the plains during the winter 
and spring months. It makes its appearance soon after the mustard plants have put 
forth their stems and are a few inches high, about October. Active reproduction 
goes on in November and December on various cruciferous plants like the cabbage, 
cauliflower, radish, turnip, etc., which are all winter crops in India. 
Severe loss is inflicted on these at this time. Young mustard shoots an. a 
favourite vegetable (Sarson kd sag) in the villages; the attack in 1913 was so bad 
that very little of it was available in places where it used to be plentiful in former 
years, and there was a widespread complaint against this destructive pest. 
On warm evenings the winged females in large numbers form a conspicuous part 
of the aerial insect fauna of the season. They are not unlike swarms of may-flies 
and frequently fall into the eyes of those walking briskly or riding a bicycle. At 
these times large numbers may be collected by hand without the aid of a net. 
The sexes are produced in December; only oviparous females were secured, 
laying eggs freely on turnip and mustard plants. Probably the alate (?) males are 
produced earlier. | 
The eggs on cabbages seem to have little chance of hatching as there is a succes- 
sion of two or three ctops in the season. There are abundant colonies of partheno- . 
genetic females, which reproduce actively after the eggs have been laid. They 
continue to do so during January and February, when again there are large swarms 
in early March which is the flowering time of mustard. The fields look like vast 
sheets of beautiful yellow with a delicate tinge of green and the occasion is celebrated 
as a fair (Basant), on which the people wear yellow turbans. Numerous Aphids are 
particularly attracted towards this coloured head-dress, though some of them settle 
on white clothes as well. 
Sexual individuals have not been found to be produced, neither is it known with 
certainty whether the winter eggs hatch at this time or not. If they do, the stem- 
mothers must be mixing their generations with those of the viviparous females from 
winter. When the mustard crop is changed for radish and cabbage they breed on the 
latter up to early June, but in diminishing numbers and even become scarce in May. 
The summer history is not definitely known ; probably they are present on stray 
plants in cold moist places. They are abundant in the hills and from there migrate 
to mustard plants again in September or October. It is also likely that later it may 
be found that they pass the summer and rainy seasons in the egg stage, 
