12 



BULLETIN 78, U. S. DEPARTMENT OF AGRICULTURE. 



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



]'<!., 1910. 



Date. 



Character of soil. 



Food plant. 



Depth. 



Inches. 

 2.5 

 3.5 

 1 



. 5 

 4 



Date. 



Character of soil. 



Food plant. 



Depth. 



1910. 

 Julv 9 



Red clay Tobacco 



1910. 

 Julv 11 

 Do.... 





Tobacco 



Corn 



Daisy 



Plantain . . . 

 Daisy 



Indus. 



1 



Co... 



do.'. 



2.5 



Do... 



do 



Plantain... 

 do 



Do.... 

 Do.... 



Do.... 



Sandy loam 



Red clay 





Do . 





1 



Do 



Black loam 



Gray sandy loam.. 



1 »aisy 



Tobacco 



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. 



Larva? 

 collected — 



Pupated — 



Moth 

 emerged — 



Num- 

 ber of 

 days. 



Larvae 

 collected — 



Pupated — 



Moth 

 emerged — 



Num- 

 ber of 

 days. 



1911. 

 June l^ 



Do 



June 20 



Do 



Do 



July 1 



1911. 



July 7-10. . . . 

 July 10-11... 

 Julv 7-9 



July 12 



Julv 15 



July 28-31... 



1911. 



July 21 



do 



July 22 



July 26 



Aug. 10 



\ 

 11-14 

 10-11 

 15-17 

 10 

 11 

 10-13 



1911. 



Julvl 



Julv 12 



Do 



Do 



Do 



Do 



1911. 



July S 



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 VJ I. — Duration of pre pupa I and pupal periods of the tobacco Crambus at Appo- 

 mattox, Va.. 1911. 



N'uin- 

 ber of 

 record . 



Larvae ceased 



feeding— 



Moth 



emerged — 



Days. 



Num- 

 ber of 

 record . 



Larvae ceased 

 feeding— 



Moth 

 emerged — 



Days. 



1 



Kill. 

 June 18 



1911. 

 July 10 



Julv 16 



Julv 18 



Julv 20 



Julv 19 



22 1 



27 



28 



15 



17 



16 



8 

 9 

 10 

 11 



1911. 

 July 9 



1911. 

 Aug. 1 



23 



2 



do 



July 11 



July 24 



July 29 



13 



:i 



do 



Julv 13 



16 



4 



Julv 3 



Julv 14 



...do.... 



20 



5 



. .do ... 



July 29 



15 



6 



...do 













