62 



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



Squares infested in laboratory 

 Oct. 23toDec. 2,19()3 



Squares picked in field May 28 to 

 June 9, 190.3 __ 



Squares picked in field Sept. 17 to 

 22,1902 



Total 



Average percentage 



Squares with ^S^^^f^ f i.'ll*^ 



rpo-e- pflpb more than 



I egg eacn. ^ ^^^ ^^-^ 



630 

 500 

 105 



1,235 



477 



317 



56 





91.7 



79.25 



62.9 



850 



84.2 



Squares with 



Doth egg 

 and feeding 

 punctures. 



135 



4-1 « 



o <c 



3.8 

 20.75 

 37.1 



13.4 



120 



3.8 

 10.0 

 43.8 



Squares fed 

 on only. 



110 

 110 

 16 



236 



o a5 



<£ U 



"So- 



S3 



17.5 

 20.0 

 15.2 



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 worlt of males and also of newly 

 emerged females before they reach sexual maturity. As the weevil 

 injuiy 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 eg^ and feeding 

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

 onlj^ 30 per cent of all injured squares contained feeding punctures, 

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

 females have access to an abundance of squares, they will deposit 

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

 posit, while the proi)ortion 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 larvje 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 Qgg 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 



