87 



a much larger proportion of the squares became infested. Corre- 

 sponding increases are seen with the third generation, but from that 

 time on so large a proportion of the squares was infested that the 

 percentage did not increase so rapidly. It may be noted in each 

 block that the maximum percentage of infestation is slightly over 90. 

 Some clean squares may always be found, however numerous the 

 weevils may be, but those which escape weevil puncture are mostly 

 less than half grown, so that while the percentage varies but slightly, 

 few of these clean squares would escape the later attacks of the 

 weevils and form blooms. In Block I the infestation was quite gen- 

 eral. The situation of the block was especially favorable to the 

 hibernation of a large number of weevils. Bounded on one side by a 

 fence row, on the opposite side by a cornfield, and at one end by the 

 buildings used by the tenant, an abundance of hibernating places was 

 afforded the weevils, and as a result they came into the field in the 

 spring from all those directions (PL XIII, fig. 51). It was noticeable, 

 however, that the portion of greatest infestation early in the season 

 lay in the corner between the fence row and the buildings. From the 

 fence row especially the weevils spread toward the center of the field. 

 The second field, as has been stated, was comparatively isolated, so 

 that infestation first began late in the season. Block I in this case 

 lay in the corner between cross-roads. Block II adjoined the road 

 farther on, while the third block was taken as far from these two as 

 was possible. Infestation began in the corner covered by Block I. 

 In studying this block, lots 1, 2, and 3, as numbered in the table, were 

 taken diagonally across the block, away from the corner. Block II 

 was separated from Block I by corn, the ends of the rows being at 

 the road which passed the point of original infestation. The lots in 

 Block II were taken in their order at varying distances from the road. 

 Block III was some distance from the others. In this case lot 1 was 

 taken along the edge on the side toward the other blocks, while lot 2 

 was taken in the middle of the block. 



Table XXIII. — Progress of infestation, field 2. 



Block 



Lot. 



Date. 



Number 

 of 



squares 

 exam- 

 ined. 



Number 



Percent- 



of 



age of 

 infesta- 



squares 

 infested. 



tion. 



45 



20.0 



351 



84.8 



12 



5.7 







0.0 



241 



66.6 



62 



33.5 



156 



86.7 



31 



15.3 



105 



77.2 



9 



6.0 



130 



65.0 



91 



41.7 



228 



88.0 



38 



22.9 



290 



88.0 



Remarks. 



II 



III 



1903 

 /August 6 . . 

 \August 22 . 

 August 6-. 



I. ...do 



\August 22 . 

 /August 13. 

 \ August 24 . 

 f August 13 . 

 1 August 24 . 

 J August 13. 

 \ August 24. 



(August 17 . 

 August 29 . 

 August 17 . 

 August 29 . 



225 

 414 

 210 



200 

 31.2 

 185 

 180 

 202 

 136 

 150 

 200 

 218 



Infestation began in this corner. 



JLot 2, in middle of Block I. 



lLot 3, opposite corner of block 

 J from lot 1. 



(Lot 1, near public road, passing 

 | lot 1 of Block I. 



Edge of block. 

 Middle of block. 



