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corn were thus treated at Mineola. The stand, however, was poor, 

 and therefore the number of ears per acre was comparatively small. 

 In these experiments each ear was opened sufficiently at the tip to 

 admit of the destruction of all larvae with the fingers. The cost of 

 the work was increased about one-third on account of the making of 

 a complete record of the number of eggs upon the fresh silks and 

 the number and approximate size of all larvae. 



For several reasons it is safe to say that the practice of destroy- 

 ing larvae of the early generations in corn, however important, will 

 never be generally adopted. In the first place it would be impossible 

 to get concerted action in work of this kind, where immediate results 

 can not be seen. The question of securing efficient labor at the time 

 the work should be done, though difficult, would be no more so than 

 that of finding time to go over large areas of corn. The practice of 

 opening the corn ears might also be objectionable in some cases, as it 

 would increase the danger of loss from decay and mildew during 

 rainy seasons. The husks should be closed after removing the 

 larvae, so as to protect the ears from injury by birds. 



At present it seems thft the plan of extermination can only be 

 profitably adopted in isolated localities and where the corn acreage 

 is small as compared with the acreage of cotton thus protected. 



Owing to the fact that the moths fly freely, entire protection to cot- 

 ton can not be insured even though all larvae are destroyed in adjoin- 

 ing cornfields — if there are such in the immediate neighborhood. 

 However, where some barrier exists, such as timber or a large field of 

 grain — the former especially — between neighboring cornfields and the 

 area for which protection is being sought, there is little danger that 

 moths will find their wa}^ in numbers to the cotton. 



THE MORE IMPORTANT NATURAL FACTORS IN BOLLWORM 



CONTROL. 



The feeding habits of the bollworm larvae afford them much pro- 

 tection from various natural enemies. The mortality from these 

 sources is therefore much greater in the egg stage than during any 

 other period of development. Numerous parasitic and predaceous 

 insects destroy a great many eggs and this is especially true where the 

 eggs are concentrated upon certain plants, as in the case of corn used 

 as a trap crop. A tiny parasite, scarcely visible to the unaided eye, is 

 responsible for the destruction of from 20 to 80 per cent of the eggs 

 laid upon corn, as well as a large percentage of those upon cotton. 

 Numerous insects feed largely upon bollworm eggs and small larvae; 

 the larvae of several ladybirds and small larvae known as aphis lions 

 are among those most beneficial in this respect. 



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