510 PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



the season after that. Of the bolls left on the sticks also, it is certain 

 that, the later they are left, the more resting larvae they contain. Heaps 

 of sticks are a very good surrounding for the further development of 

 the insects, though perhaps the best environment is on the ground in 

 sufficient shade to prevent the temperature rising above 50° C. It has 

 been stated earlier, that the rise in percentage attack of green bolls 

 from 25 per cent, to 75 per cent, passes through in three or four weeks. 

 This takes place roughly at the time of the first picking. 



The whole question of Pink Bollworm control centres in the 

 possibility of early removal of growing cotton plants from the fields. 

 A very imperfectly conducted campaign in September would give better 

 results than an obtainably perfect one at the end of October, but unfor- 

 tunately this is not yet agriculturally a possibility. 



The treatment of the seed is without doubt also of importance,, 

 but cannot compare in this respect with the fieldwork. Excellent 

 work done on a small area is useless, unless the surroundings are far 

 and wide equally well cleaned. And imperfect w^ork of one year is 

 certain to make itself felt for two following years, even if the first of 

 those two following years should be conspicuous by good work. This 

 is due to the fact that a comparatively large proportion of resting worms 

 can and do survive to the second following summer before pupating 

 and emerging as moths. 



Two experiments have been made in 1917, to test the plan of the 

 campaign, one at Tel el Kebir, where in a large area isolated to a great 

 extent by desert on both sides, the land was swept after the last crop 

 was taken, and where the bolls were very thoroughly destroyed and 

 this year was planted with treated seed. The area was looked after 

 by several moawens. One part of it showed exceptionally high infection 

 this year as compared to the others, and it was afterwards found by 

 inquiry, that the moawen at first in charge of that part had had to be 

 disciphned for neglect of duty and corruption. 



For the first part of the season the whole area however was consider- 

 ably better judging by percentages of green bolls attacked than in the 

 corresponding part of the previous year. Towards the end of the season 

 it deteriorated, but was even so better than at the corresponding period 

 of the previous season. Part of the deterioration may be due to larvae 

 of two seasons earlier. 



The other experiment was made at Armant in Upper Egypt. This 

 place was left alone. The cultivators know the law, and its objects, 

 but without driving by the agents of the Government may be relied 

 on doing nothing towards destroying the bolls at the end of the season. 

 There has been a high rise of infection percentage of green bolls recorded 



