10 PROCEEDINGS OF THE SECOND ENTOMOLOGICAL MEETING 
point of view of control this is of some importance, as 
measures taken on the first appearance of the insects after 
hibernation may be rendered abortive, or will at least require 
to be supplemented, in view of these late emergences. 
An observation of this kind, apparently trivial in itself, 
emphasizes the fact that an intimate knowledge of the 
habits of the insects concerned must be the first step towards 
their control.” k 
This seems to me an excellent illustration of the necessity for exact 
observations and records of even the commonest insects, for, as I have 
pointed out in the extract which I have just read to you, any successful 
measures of control of such insects must be based on a very exact 
knowledge of their lifehistories. 
An interesting confirmation of these remarks has lately come to 
hand in a voluminous report recently published by Mr. Willcocks on 
the Insect Pests of the Cotton Plant in Egypt, of which Part I deals 
with the Pink Bollworm (Gelechia gossypiella) which, as you all know, 
occurs commonly throughout India also. In November 1913 Willcocks. 
took fifty thousand larvee of G. gossypiella and placed them in a large 
cage and observed the emergence of the resulting moths ; he found 
that they emerged right up to 28th August 1915, the largest numbers 
of emergences being in November 1913—January 1914, July-October 
1914, and April-August 1915, this last lot bemg much smaller in number 
than the two previous lots. Now, an experiment of that sort throws a 
ereat deal of light on the question of control ; for even if no cotton had 
been available for the whole of the year 1914, cotton grown in 1915 
might still have been attacked by caterpillars from parents which had 
fed up two years before. As regards the application of these results 
to India, we are quite in the dark as to whether the same conditions. 
hold. Taking the case of Gelechia gossypiella, we do not know, as a 
matter of fact, how long a period may emerge between the times when 
the larve are full-fed and the emergence of the moths. Yet experiments 
on these lines—the simple collection of full-fed caterpillars and breeding 
out of the moths—are open to each one of you. But it as little use to 
take a dozen or so caterpillars and expect to get much in the way of 
results. You must deal with large numbers to avoid experimental 
errors and get good results. 
In the next year’s Report for 1915-16, I wrote :— 
“Large numbers of Fruit-flies were reared out to discover to 
what extent they are checked by parasites, but it was found 
that the proportion of parasites is extremely low. The 
only Fruit-fly which is parasitized to any appreciable extent 

