38 



THE GRAPE ROOT-WORM. 



or destroyed some time before the post-larval period, a new one is 

 readily made, and, as a rule, within a shorter time than was required 

 for the making of the first cell. As recorded in Table XV, individual 

 No. 21, a larva made the second cell and pupated within 9 days. 



Table XV. — Observations on the transformations and habits of the pupa and the beetle, 

 of the grape root-worm in the soil, from breeding experiments at North East, Pa., 1909. 



Number of individual. 



Date. 



Days. 



Making 

 of cell. 



Pupa- 

 tion. 



Trans- 

 formed 

 to beetle. 



Left the 

 cell. 



Making 

 cell. 



Pupal 

 stage. 



Beetle 

 in cell. 



1 



May - 

 May - 

 May - 

 May - 

 May — 

 May - 

 May - 

 May 30 

 ...do 



June 17 



...do.... 



...do 



June 15 

 June 20 

 June 19 

 June 21 



...do.... 

 June 20 

 June 21 

 June 24 

 June 20 

 June 21 



...do 



June 30 

 July 1 

 July 2 

 June 30 

 July 7 

 July 9 

 July 10 



...do 



July 2 

 July 9 



...do 



...do.... 

 July 10 



...do 



July 6 

 (Died).. 





13 

 14 

 15 

 15 

 17 

 20 

 19 

 19 

 12 

 18 

 15 

 19 

 19 

 19 

 18 

 19 

 19 

 19 

 18 

 18 

 20 

 18 

 20 

 21 

 17 

 18 

 18 

 18 

 17 

 19 

 21 

 18 

 19 

 16 

 18 

 20 

 18 

 17 



6 



2 





3 



do 







4 



July 5 





5 



5 





6 









7 



July 14 



...do 



(Died).. 

 July 13 

 July 14 

 July 13 

 do 





4 

 4 



8 



22 

 21 



9 



10 



May — 

 May 30 

 May - 

 May - 

 May — 

 May — 

 May 30 

 do 



4 

 5 

 4 

 3 

 4 

 4 

 7 

 6 

 3 

 4 



11 



25 



12 



13 





14 



July 14 

 July 13 

 July 16 

 July 13 



...do 



...do.... 





15 



...do.... 

 June 20 

 June 18 

 June 21 

 ...do.... 

 ...do 



July 9 



...do 



July 7 

 July 10 

 July 9 





16.. 



21 

 19 

 22 

 22 

 14 

 9 

 25 

 14 

 14 

 31 

 28 

 28 

 28 



17 



18 



...do 



19 ; 



20 



...do.... 



June 7 



do 



21 



do 



July 6 

 July 12 

 July 11 

 July 13 



jiily'li' 



...do 



...do.... 

 July 12 

 July 14 

 July 23 

 July 10 

 July 12 

 July 11 

 July 14 

 July 15 

 July 17 

 July 8 



July 13 

 July 16 



7 

 4 



22 



May 30 

 June 7 

 June 8 

 May 26 

 do 



June 16 

 June 24 

 June 21 

 June 22 

 June 26 

 June 23 



...do.... 

 June 25 



...do.... 

 June 2 

 June 22 

 June 23 

 June 25 

 June 26 

 June 25 

 June 29 

 June 21 

 June 10 

 June 23 

 .do 



23 



24. .. 



July 16 

 (Died).. 

 July 14 



...do 



...do.... 

 do. 



3 



25 



26 



3 

 3 

 3 



2 

 4 



27 



...do 



28 



29 



...do.... 



30 



May 30 

 do 



July 18 



26 

 33 

 23 

 24 

 21 



31. .. 



32 



...do 







33 



do 







34 



June 4 



July 17 



6 



35 



36. .. 





July 17 





2 



37 







38. 











39 



May 31 

 June 5 

 June 8 





10 

 18 

 15 





40 



July 11 



July 15 



18 



4 



41 . . . 



Total. 













513 



696 



104 









1 



Table XVI. — The making of the pupal cell, the pupal period, the beetle in the cell; 



summary of Table X V. 



Average. 



Maximum. Minimum 



The making of the pupal cell 



Pupal stage 



Beetle in cell 



Days. 

 21.4 

 17.8 

 4.1 



Days. 



Days. 

 9 



12 

 2 



THE POST-LARVAL STAGE. 



During the post-larval stage the grub undergoes marked structural 

 changes and is in this condition extremely delicate and helpless. The 

 body is slightly shortened, and the curved grublike appearance is modi- 



