INTRODUCTION. 
Aphididae or plant-lice are soft-bodied, usually small insects belonging to the 
same large group popularly known as “bugs.” Like them constituted to live upon 
liquid food only, they draw out their nutriment by punc- 
turing the living parts of plants, by means of their suc- 
torial beaks. It is due to their sedentary habits and quick multiplication that they 
are generally found in smaller or larger droves, most frequently upon the leaves and 
the tender shoots of their hosts. If the drain upon the juices is excessive, the plants 
are very much weakened, and even succumb to the injury. 
Those therefore that attack the cultivated plants often 
assume an economic importance for the gardener and the farmer, necessitating vigor- 
ous, and in cases even elaborate, measures to be taken in hand to stop or stem the 
fe due to these pests. 
Their biological interest and importance is no less great. They present several 
unusual and remarkable peculiarities in their structure and life-histories. Their . 
study has attracted numerous workers, but still the group 
requires a thorough investigation from several aspects. 
The popular English names for these insects are ‘‘ green-fly blight’’ or ‘‘ plant- 
lice.’ The German ‘‘ Pflanzenlause’’ is an exact equivalent of the latter, though 
equally often they are referred to as “ Blattlause ’’ or ‘‘leaf-lice.”’ 5 
There is hardly any word in use in the Punjab to definitely designate a ‘‘ plant- 
Aphids. — 
Economic importance. 
Biological interest. 
louse.’’ Ordinarily the farmer speaks of it as ‘‘ Tela’’ from ‘‘tel,’’ meaning oil, 
Vie pnaculatanome which has a reference rather to the effect of its presence 
Tela.” upon the attacked plant. When clustering in large numbers 
on the young branches and constantly sucking the juice, the insects void out thin and 
clear saccharine excreta, known as ‘‘ honey-dew,’’ which falls in fine drops over the 
lower parts of the plant. These come together and smear the leaves, or flow down 
the branches. On drying up a little, this liquid takes the appearance and consistency 
of a syrup or a non-volatile oil with which the plant seems to be sprinkled over 
Moreover, the branches thus wetted, and the smothered vegetation below these, 
when dried and ignited, burn as if they had been soaked in some inflammable 
material. Hence the propriety of naming it ‘‘Tela.’’ But the indefiniteness about 
this name is that a similar effect may be caused by insects other than Aphids, and in 
that case the other insects are also termed ‘‘ Tela.’’ For instance we have ‘ Mango 
„ 
Tela,’’ which is a Psyllid; ‘‘Sugarcane Tela,” that is an Aleurodes; or ‘ Banyan 
(Zrcus bengalensis) Tela,’’ that may be a Coccid (Monophlebus). 
In the United Provinces an individual Aphid is called by the agriculturists 
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