_ IT 



The younger of the two generations is the winter-feeding brood. 



From the figures given in the table it is quite easy to trace the 

 slow growth of the individuals composing it during December, January, 

 and February. By March all but nine per cent of this generation were 

 full fed. As the last picking in the fields from which these bolls were 

 collected took place on October 26, and the cotton sticks were removed 

 from the fields on or before November 3, 1915, there appears to the 

 writer to be considerable probability that the eggs from which the 

 larvae forming the winter-feeding generation were derived must have 

 been laid on bolls on the ground. Should this be actually what 

 happens, bolls left on the ground after the last picking acquire a still 

 greater economic importance than they already had. 



Having found that Gdechia larvae readily survive in bolls lying on 

 the surface of the ground amongst cultivated crops, where the bolls 

 are liable to rot and where they must be- submerged every time the 

 fields are irrigated, it is not surprising to find that many of the larvae 

 that are buried at the time of preparing the ground for the crops 

 survive. As it was difficult or even perhaps impossible to find such 

 bolls by digging in the fields, experiments in thii direction were made 

 in the grounds of the Ministry of Agriculture at Cairo. 



Seed containing larvae and "double" seeds were used, on account 

 of the difficulty in procuring bolls at the time when the experiment 

 was started (December 23, 1915). Two series of experiments were 

 made ; small flower pots were prepared by having the drainage hole 

 being stopped by plaster of Paris. One set of these pots, Series I, was 

 filled with apparently good cotton seed, fifteen full fed Gdechia larvae 

 placed in the seed, the pots were then closed by tying muilin over the 

 opening. In the second set, Series II, the pots were filled with infested 

 seed (" double " seed) instead of sound seed with isolated larvae. 



The further treatment of both these sets of pots was exactly the 

 same. One half of them were buried in dry ground, in land left 

 unwatered except by rain, the other half was buried in land on which 

 a crop of bersim was grown. 



To test the influence of depth at which the seed was buried part 

 of the pots were lowered until their tops were five, ten, fifteen, and 

 twenty centimetres from the surface. 



From these experiments the depth factor does not appear to be 

 an important one, and Gdechia larva) seem to support being buried 



