MINISTRY OF AGRICULTURE, EGYPT. 



\o. 4. 



(KNTOMOIA )( MGAL SECTION.) 



THE LIFE HISTORY OF GELECHIA GOSSYPIELLA 



FROM THE TIME OF THE COTTON HARVEST 



TO THE TIME OF COTTON SOWING. 



The whole problem of the. control of Gdechia gossypidla Saund. 

 is closely bound up with the solution of the question where and how 

 Gdechia passes the late autumn and winter. 



As is well known in the summer, from June onwards, Gelechia 

 gossypidla passes through many generations, each of which lasts 

 only a few weeks. Each successive generation is immensely more 

 numerous and more important in the damage it does, than the preceding 

 one. Towards late autumn, however, we find a change; with the 

 advent of colder weather the larvae no longer pupate, but hibernate 

 unchanged when full fed, pupation taking place, on the advent of 

 warm weather, next spring. 



The object of this paper is to show what happens with the seed 

 worm between the time of the first picking and the time of sowing, 

 this being the period during which the pest can be controlled most 

 effectively. 



It is so well known to cultivators and ginners that it is not 

 necessary to insist on the enormous increase of the pest between the 

 first and second pickings. As a general rule the first picking is 

 affected only to a slight degree, whilst the second is seriously damaged, 

 and if the harvesting of a third picking were attempted, it would in 

 most places be found to be worthless. Four or five years ago three 

 pickings appear to have been the rule, but this year, owing .to Gdechia 

 attacks, few cultivators in Lower Egypt obtained a third picking. 



The increase of the pest between the first and second pickings 

 can be most easily gauged by examination of commercial cotton s 



