12 



BULLETIN 78, U. S. DEPARTMENT OF AGRICULTURE. 



Table V. — Depth at which pupation of the tobacco Crambus takes place, Appomattox, 



Va., 1910. 



Date. 



Character of soil. 



Food plant. 



Depth. 



Date. 



Character of soil. 



Food plant. 



Depth. 



1910. 

 July 9 

 Do 





Tobacco 



.do 



Inches. 

 2.5 

 3.5 

 1 

 .5 

 4 

 3.5 



1910. 

 July 11 

 Do 



Red clay 



Tobacco 



Corn 



Daisy 



Plantain... 

 Daisy 



Inches. 

 1 





do 



2.5 



Do. . 



do 



Plantain... 



do 



Daisy 



Tobacco 



Do.... 

 Do.... 

 Do.... 



Sandy loam 





Do 



Red cla}- 



Black loam 



Gray sandy loam. . 



1 



Do... 



do 



1.5 



July 11 









Numerous measurements made at different times gave results very 

 similar to those shown above. The average depth at which pupation 

 takes place was found to be about 1.5 inches. 



The cells averaged about 9.5 mm. in length and 4.5 mm. in width 

 (inside measurements). The lower portion of the cell is usually 

 somewhat larger than the upper portion, the pupa lying in the larger 

 end of the cell in convenient position for its egress. The cells are 

 extremely fragile and are easily broken when removed from the soil. 

 They are constructed of fine particles of earth and grains of sand in- 

 terwoven with a silky weblike material. The walls are thin and the 

 interior surface quite smooth. 



The pupal period, as shown in Table VI, lasts from 10 to 15 days. 



Table VI. — Pupal period of the tobacco Crambus, Appomattox, Va., 1911. 



Larvae 

 collected — 



Pupated— 



Moth 

 emerged— 



Num- 

 ber of 

 days. 



Larvae 

 collected — 



Pupated— 



Moth 

 emerged — 



Num- 

 ber of 

 days. 



1911. 

 June IS 



Do 



June 20 



Do 



Do 



Julv 1 



1911. 

 July 7-10. . . . 

 July 10-11. . . 



July 7-9 



July 12 



July 15 



July 28-31... 



1911. 



July 21 



do 



July 22 



do 



July 26 



Aug. 10 



1 

 11-14 [ 

 10-11 

 15-17 1 

 10 



ii ! 



10-13 j 



1911. 



July 1 



July 12 



'Do 



Do 



Do 



Do 



1911. 



July 8 



Aug. 1-3.... 



July 15 



July 28-31... 



Aug. 1-2 



Aug. 1 



1911. 



July 22 



Aug. 15 



Aug. 1 



Aug. 10 



Aug. 15 



Aug. 12 



14 

 12-15 



15 

 10-13 

 13-15 



12 



Table VII shows the duration "of the period during which the 

 insect is in the pupal cell before and after pupation. 



Table VII. — Duration of prepupal and pupal periods of the tobacco Crambus at Appo- 

 mattox, Va.. 1911. 



Num- 

 ber of 

 record. 



Larvae ceased 

 feeding— 



Moth 

 emerged — 



Days. 



Num- 

 ber of 

 record. 



Larvae ceased 

 feeding — 



Moth 

 emerged — 



Days. 



1 



1911. 



1911. 

 July 10. ...... . 



July 15 



Julv 10 



July 18 



July 20 



July 19 



22 



27 

 28 

 15 

 17 

 16 



8 

 9 

 10 

 11 



1911. 

 July 9 



1911. 

 Aug. 1 



23 



2 



do 



July 11 



July 24 



July 29 



Aug. 3 . 



13 



3 



do 



July 3 



Julv 13 



16 



4 



July 14 



20 



5 

 6 



do 



..do 



do 



July 29 



15 









