62 



Table XV. — General results of observations upon selection of squares. 





■3 



© 



•j 



'is 



I 

 7. 



Squares with 

 1 egg each. 



Squares -with 

 more than 

 1 egg each. 



Squares with 



both egg 

 and feeding 

 punctures. 



Squares fed 

 on only. 





© 



a 



Percentage of 

 all squares 

 receiving 

 eggs. 



2 

 1 



o © 



C S fr 



Ah 



1 



pi 

 fei 



© h 



II 



PS 



© 



! 



O 00 



Z. ® 

 © u 



|i 



g* 



S3 



£2 



Squares infested in laboratory 

 Oct. 23 to Dec. 2.1902 



Squares picked in field May 28 to 

 June 9, 1903 . 



630 

 500 

 105 



177 91. 7 

 317 79.25 

 56 62.9 



19 

 83 

 33 



3.8 

 20. 75 

 37.1 



21 

 50 



3.8 



in n 



110 



110 



16 



17.5 

 20 



Squares picked in field Sept. 17 to 

 22,1902. 



16 13.8 



15.2 



Total J 1 ? 235 I 850 ; 



Average percentage L 81.2 



135 



120 



13.1 



236 



18.3 



A few obvious conclusions may well be stated here. Throughout 

 the season from one-fifth to one-sixth of the squares injured were 

 destroyed by feeding punctures alone. Within this small portion 

 must be included most of the work of males and also of newl}' 

 emerged females before they reach sexual maturity. As the weevil 

 injury overtakes the production of squares it becomes increasingly 

 difficult for females to find clean squares, and they are forced to 

 deposit eggs in squares already injured and also to feed upon squares 

 which already contain eggs. These conditions serve to increase most 

 rapidly the proportion of squares containing both egg and feeding 

 punctures. This is still further emphasized by the fact that in June 

 only 30 per cent of all injured squares contained feeding punctures, 

 while in September nearly 60 per cent had been thus injured. When 

 females have access to an abundance of squares, thej- will deposit 

 more than one egg only in about one-fifth of those in which they ovi- 

 posit, while the proportion of those having both egg and feeding 

 punctures is still smaller. 



The tendencies to keep egg and feeding punctures separate, as well 

 as to deposit only one egg in a square, serve to produce the greatest 

 injury of which the weevils are capable for two obvious reasons : First, 

 because where several eggs are placed in one square it is rarely the 

 case that more than one larva develops. If two or more hatch in a 

 square, one is likely to destroy the others when their feeding brings 

 them together. They bite savagely at anything which irritates them, 

 and larvge have been found in the actual death struggle. Second, 

 should eggs be placed in squares which already contained a partly 

 grown larva, those hatching would likely find the quality of the food 

 so poor that they would soon die without having made much growth. 

 One egg will insure the destruction of the square, and a number of 

 eggs, could all the larvae live, would do no more. Therefore it is 

 plain that the possible number of offspring of a single female is 



