o 



and much more attention would have to be paid to preventing bolls 

 falling to the ground and being left there to rot. In combating 

 Earias, bolls left on the ground did not have the same significance as 

 they have in the control of Gelechia. 



It can be considered as certain that all Gelechia larvae arriving 

 at maturity after the middle of October are going to hibernate before 

 pupation. As we have seen above, it is the hibernating larvae which 

 arc chiefly responsible for carrying on the pest from one season to the 

 other. The later the bolls are left on the plants or in the field, the 

 more certain they are to be infested by Gelechia larvae. It is con- 

 sequently urgently to be recommended that the final destruction of 

 immature or worthless bolls should take place at the time of final 

 picking. 



It has been almost impossible this year to obtain bolls for exam- 

 ination in January from cotton sticks or from cotton plants left 

 standing in the fields or stored as fuel. That such bolls are a favourite 

 hibernating place for Gelechia larvae is well known. We have, however, 

 been able to examine a number of bolls collected at Giza in October 

 1915. These bolls were stored in the insectarium of the Entomological 

 Section, no special care being given to them. On February 21, 1916, 

 seventy-six bolls were examined and were found to contain five small, 

 eight half-grown, and thirty-nine full-grown living Gelechia larvae, 

 fourteen dead larvae, and two empty pupa cases of Gelechia. In addi- 

 tion to these three empty pupa cases of Pyroderces gossypiella Wlsm., 

 one Earias insidana pupa, and one dead Pimpla roburator F. were 

 found. Seventy-five cotton bolls found on sticks, used as supports 

 fcr peas, were collected in a garden near Cairo in February 1916; these 

 contained two small, three half-grown, and one full-grown Gelechia 

 larvae. 



The destruction of the bolls to be really effective must be complete. 

 Fellahm do not realise that bolls fallen to the ground are as great a 

 menace to the next year's crop as bolls left on the cotton sticks, and 

 very much more serious than the worms left in the seed. 



In order to ascertain what happens to worms in bolls lying on 

 the ground, two sets of examinations have been made. In one case 

 bolls have been collected from the ground in the field amongst growing 

 crops, in the other, seed and bolls containing worms have been buried 

 at various depths under growing bersim as well as in unwatered land. 



