140 Memoirs of the Indian Museum. [vor. VI, : 
(2) Its general appearance may be sickly and the lower foliage smeared with 
an oily liquid over which a deposit of fine dust renders it still more 
unsightly. 
(3) This liquid serves as an excellent culture medium for the growth of the 
sooty fungus Capnodium, sometimes only in its ‘‘Fumago” stage 
The latter forms black smoky incrustations over the leaves, blocks their 
light, and on drying up scales off in thin flakes. The more abundant 
the excreta or ‘“honey-dew’’ of the aphids, the greater is the growth of 
the fungus. Whole fields may thus be blackened and smothered in 
some cases. | 
(4) Predaceous insects such as Coccinellids (ladybird-beetles) may be noticed 
in the vicinity, and these insects always possess conspicuous, warning 
colours. Their shape, like half a pea, is also characteristic. Syrphid 
flies, too, hover about the infested plants in order to deposit their white 
eggs, and can be recognised by their bright banded abdomens. 
(5) A very sure sign again is the presence of ants coursing up and down the 
plant. Even when there are just a few aphids hiding themselves under 
a leaf, ants would discover them much quicker than any trained collector 
of insects. Ants are too notoriously fond of sweet things, and seek out 
the plant-lice for the ‘‘honey-dew”’ they discharge. To this fondness 
may be ascribed those extraordinary relations existing between ants 
and aphids into which at present we need not go. Lubbock, Busgen, 
Forbes, Mordwilko, Wheeler and Webster have written on the subject. 
Like the majority of other Hemipterous insects plant-lice do not undergo any 
true metamorphosis. The normal course of their life-history in Lahore, with slight 
Metamorphosis and Life- Variations, is about the same as in other countries, and may 
cycle. be briefly told as follows:— 
Eggs.—-The eggs are deposited during winter from any time in December to ae 
February. They are long oval in form, varying in length from 0-5 mm. to 1°5 mm., 
and are generally laid scattered near or upon the host buds, but in some forms as 
clusters also. The light colour of the freshly laid egg soon changes into shining jet 
black, a characteristic of the aphids. 
The hatching period extends from late February to about June in some species. 
The insects that emerge are wingless, and remain so till maturity, that is fifteen or 
twenty days later, when they begin to reproduce parthenogenetically. Several 
broods of similar ‘‘ asexual’’ or ‘‘agamous’’ females, all giving birth to live young, 
may follow, and are spoken of as ‘‘ apterous viviparous females.’’ 
Stem-mothers.—The original females from which the later generations spring are 
called ‘‘ stem-mothers’’ or ‘‘ Fundatrix.’’ 
Ecdyses.—The time taken by each female, from its birth to the age when repro- 
duction begins, differs according to season and species from four or five days to 
twenty or more. During this interval there are usually four or five ‘‘ecdyses ” or 
skin-moults, 
