43 



rapidity of increase in the foliage area shown in the first part of 

 Series I shows that spraying must be repeated every week or ten days 

 if even one-half of the entire leaf area is to be kept poisoned. When 

 in connection with the large per cent of daily increase we consider 

 how much of that percentage is being unfolded at the very tip of the 

 stem ; that upon that limited tip area alone will* the weevil feed before 

 the formation of squares; that after the formation of squares it 

 appears to be absolutely impossible to poison the weevil's food sup- 

 ply, and also that the irregular emergence of the weevils from hiber- 

 nation may extend through several weeks, it at once becomes evident 

 that spraying early cotton for hibernated weevils is almost as imprac- 

 ticable as the spraying of older cotton is now acknowledged to be. 



EFFECTS OF FEEDING UPON SQUARES AND BOLLS. 



From numerous large, open, feeding punctures a square becomes 

 so severely injured that it flares very quickly, often within 24 hours. 

 Males usually make the largest punctures, and always leave them open 

 while they remain for a day or more working upon the same square. 

 It has been often found that squares thus injured by a male will flare 

 before the weevil leaves it. The time of flaring depends upon the 

 degree of injury relative to the size of the square. Thus, small squares 

 receiving only a single large feeding puncture in the evening are found 

 widely flared in the morning. On the other hand, large squares which 

 are within a few days of the time of their blooming may receive a 

 number of punctures without showing any noticeable flaring. Fre- 

 quently a square which has flared widely will be found later to have 

 closed again and to have formed a distorted bloom (PL YI, fig. 30; PL 

 VII, fig. 31), and occasionally such squares develop into normal bolls. 

 In squares of medium size a single feeding puncture does not usually 

 destroy the square. The destruction of a square by feeding results 

 either from drying, decay, or a softened, pulpy condition of the 

 interior which is the consequence of the weevil injury. 



Bolls are quite largely fed upon after infestation has reached its 

 height. Small and tender bolls are often thoroughly riddled by the 

 numerous punctures (PL VII, fig. 32). Small bolls so severely injured 

 fall within a short time. Larger bolls may receive more punctures 

 without being so severely injured. A comparison of the external 

 and internal effects in such cases is shown in PL VIII, figs. 34, 35. 

 Abnormal woody growth takes the place of the normal development 

 of the fiber, and a softening and decay of the seeds often accompanies 

 this change. One or more locks may be destroyed while the remain- 

 der of the boll develops in perfect condition (PL VII, fig. 33; PL X, 

 fig. 38). 



After the bolls become about half grown the effects of feeding are less 

 liable to cause the boll to fall (PL I, fig. 10). The puncture becomes 

 closed by a free exudation of the sap and a subsequent wood}^ growth, 



