72 



number of larvae were supplied with both kinds in the laborator}^ and 

 their selection noted. The following table gives the preferences of a 

 lot of ten young larvae on succeeding days: 



Table XXIV. — Relative attractiveness of King and Mit Afifi cottons. 



Kind of cotton. ^^^^ 



Second 

 day. 



Third 

 day. 



Fourth 

 day. 



Fifth 

 day. 



Sixth 

 day. 



Seventh 

 day. 



Eighth 

 day. 



Total. 



King ..1 7 i 9 



Egyptian (Mit Aflfi) 2 1 



8 



2 



5 

 4 



7 

 3 



8 

 2 



6 

 3 



6 

 3 



56 

 20 



COMPARATIVE INJURY TO EARLY AND LATE COTTON. 



Planters have been taught b}^ the accumulated experiences of many 

 years that early-planted cotton is much less subject to the ravages of 

 the boUworm than cotton planted late. This fact has also been noted 

 b}^ manj^ observers, not onl}^ with reference to the bollworm, but to 

 other cotton insects. Thus Riley, as early as 1885, says: 



Our knowledge of the natural history of Aletia [Alabama argillacea'] and the yearly 

 occurring experiences with its ravages teach us that the principal and most effective 

 means of prevention is to hasten the maturity of the plant so that a portion of the 

 crop shall be beyond the reach of harm from the more destructive July and August 

 broods of the worm. 



Improving the cotton seed in the direction just mentioned can be accomplished 

 principally by careful selection of early varieties of cotton or by introducing seeds 

 from more northern regions. Early planting is to be strongly urged in this connec- 

 tion, although, of course, it has its drawbacks in the risks of exceptionally late falls. « 



Professor Mally, in discussing certain statistics of the relative injurj^ 

 of boll worms to earl}^ and late cotton in Texas in 1892, sa3''s: 



The late cotton, therefore, shows a loss of 50.6 per cent, while the early cotton 

 shows no real loss. This may be taken as an extreme case, but the general principle 

 remains that late cotton receives by far the greater portion of bollworm attack, 

 virtually protecting the cotton fields about it. '^ 



The decided preference of bollworms for squares and 3^oung bolls, 

 as compared with mature and more hardened bolls, is shown in the 

 following table, as is also the comparative injury to early and late 

 planted cotton. 



« Riley, Fourth Rept. U. S. Ent. Com., p. 120. 



6 Mally, Rept. on the Bollworm, 1902, p. 12, Austin, Tex. 



