14 



CONCLUSIONS. 



(1) The distribution of pink boll worm attack in cotton bolls 

 follows definite rules in Sakelk rides cotton. 



(2) For any given percentage attack it is possible to calculate the 

 numbers of bolls per hundred with 0, 1, 2, 3, 4 and more worms. 



(3) The damage is directly proportionate to the number of worms 

 which have attacked the bolls. 



(4) The damage done by a single worm is about one tenth of the 

 yield of the boll in Sakellarides cotton. 



(5) When the percentage attack is known, it is possible to predict 

 the number of bolls per hundred attacked in 0, 1, 2, or 3 locks, whereby 

 there is evidence that about one worm in four does damage to more 

 than one lock in Sakellarides cotton. 



(6) It is obvious from the study of the facts brought forward 

 that it is not permissibile to make averages of percentages attack of 

 bolls, if averages are required they must be made after converting 

 the figures for percentage attack into numbers of worms per hundred 

 bolls or into percentage damage done. 



EXPLANATION OF TERMS USED. 



(1) Entire population of bolls. 



All the bolls set on the plants under examination, whether they 

 mature into pickable cotton or no, including even such bolls as fall off 

 before maturity. 



(2) Select population. 



That part of the population which has been selected according to 

 any method, or for any purpose. 



(3) True percentage. 



The true percentage is the percentage over the entire population. 



(4) Apparent percentage. 



The percentage observed when examining a select population. 



(5) Percentage attack. 



The number of bolls per hundred which have been attacked by 

 the insect. 



(6) Percentage damage. 



The loss to the crop due to the ravages of the pink boll worm. 

 Until 100 per cent attack is reached the percentage damage is always 

 smaller than the percentage attack. 



