293 
In Egypt Gelechia gossypiella, Saunders, can have several 
generations each year; some individuals, however, require 
much longer to develop than others, and thus the number of 
generations varies from one brood to about six. The longer 
broods have a hibernation or estivation period as larve, when 
full grown after finishing feeding and before pupation. This 
period may last only one week, or be protracted indefinitely 
with the larve subjected to the same conditions. 
The pink boll-worm is attacked by the following parasites: 
Pimpla roborator, Chelonella sulcata, Limnerium interruptum, 
Pediculoides ventricosus, Microsporidium polyedricum. These 
parasites can cause damage up to 40 per cent., or perhaps even 
more, to hibernating larve. The effect of the control exer- 
cised by the parasites is already noted in the field; wherever 
records are available the attack by Gelechia has been worst in 
the second year, being much reduced in the third. 
The amount of damage done is very difficult to estimate. 
In the cotton-growing season of 1913 Gelechia larve did the 
greatest amount of damage hitherto recorded for them in 
Egypt, yet in spite of this the exportation of cotton lint 
reached record figures. Of course the quality may have 
deteriorated. Damage to seed is more obvious, about 10 per 
cent. on the average having been damaged and made infertile, 
thus reducing the germination of average seed from 85 to 75 
per cent. From the point of view of sowing, this makes no 
great difference, as the Egyptian cultivators invariably sow 
from eight to twelve seeds in a hole, and later on eliminate all 
but two of the seedlings. 
The only remedies available against this pest are the destruc- 
tion, during the winter, of all bolls on cotton sticks stored for 
fuel, and the fumigation or other treatment of the cotton seed 
in the ginneries. The first of these two requirements has been 
made the subject of proposed legislation, and it is hoped 
that the second will be voluntarily done by the ginners, as we 
have shown the possibility of complete destruction of all larve 
in cotton seed by fumigation in circulating carbon disulphide 
vapours, or in circulating hydrocyanic acid or sulphur dioxide 
gas, as well as by suitable treatment with hot air or by 
immersion in weak solutions of cyllin. 
[Discusston. ] 
The CHarrman: I think you will all wish to thank Dr. 
Gough for his interesting paper, which illustrates very well 
the dangers which all countries have to face so long as there 
are no international laws for regulating the importation of 
seeds, plants, etc. It is a question which we discussed here 
the other day. 
