26 BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. 
The 551 weevils bred under field conditions from squares of all 
three types of cotton required a total of 12,012 weevil days or an 
average period of development of 21.8 days from egg to adult. 
The average developmental period of the weevil in all three types 
of cotton squares under insectary conditions is shown in Table XIII 
to be 14.3 days from ege to adult. The average developmental 
period under normal field conditions for weevils bred from all three 
types of squares is shown to be 21.8 days. Under actual field condi- 
tions it is safe to say the boll weevil requires a period of 7.5 days 
additional time for development, or fully one-half more time than is 
required under insectary conditions at Madison, Fla. 
TABLE XIJI.—Table showing the developmental period of the boll weevil under 
insectary conditions, 1919. 
Sole |S Se | eicsie |e 
Sb OS H ln Slo mR |S5/ 0 ay 
Period of ovi: |95| 2] & |°S|Fa| & |en| ee] & 
Nature of weevils. lbp NO~l) See Se | Piak o isa Se) 6 | sf Pl o 
position. 5 S| &m |1Poli PS] w» | as S| eH 
POPS be iacias |S Ieeiac [s 
SCS eis PE Nae) es) 2 
Z | 412 j= |< je |e a 
Days Days Days 
Mibernateds-2 22-5... -- Upland cot- | June 5-July 25 | 247| 3,692) 14.9) 123/1,816| 14.7] 370} 5,508) 14.8 
ton squares. 
Hirstigenerations=s-e-selsasce ese eee ee July 5-Aug. 19 | 189} 2, 765) 14.6) 117/1, 762) 14.3] 306) 4, 438] 14.5 
MOVER bt OEE OTCG I i aE ee Saas 436] 6,457) 14.8) 240/3, 578) 14.5} 676] 9,946) 14.7 
cotton. 
Long-staple cotton: 
First generation...| Long-staple | July 9-Aug. 2 210] 2, 953/14.06| 154/2,187| 14.2} 364] 5,140) 14.1 
squares. 
Sea-island cotton. 
First generation...| Sea-island | July 5-Aug. 9 67} 917) 13.6) 41} 565) 13.7) 108) 1,482) 13.7 
squares. 
Notaliallcottonks eeeeeacesere cel oeecocmeneer eens 713/10, 327/14. 15} 435)6, 330} 14. 1/1, 148/16, 568) 14.3 
TABLE XIV.— Showing the total developmental period of the boll weevil under 
field conditions. 
Males. Females. Both sexes. 
a 2 . 1 I . fw Fat co} 
f : pes Sy 8 eal 3 3 > Sy 
Nature of weevils. | Larvalfood.| Petiodofovi ),S| RE) & jsSio | 8 |e | 3 iss 
position. Sia hs Sed lo Sy) a Bd/ ed aie 
og| ae | 8 |Szlee|e| £/ e/e2 
Heles| § esis~| & |e |S" lss 
SUES ay eis fe use 
Z a <4 |4 | < 18 a <q 
Upland cotton: Days Days Days 
Hibernated....... Cottonsq...| May 29-June 13. 73) 1, 536] 20.9} 52/1, 145)22.91) 125) 2,681) 20.8 
ID) Q)pAe ae ae downs June 7-June 22. 23) 477) 20.7) 27| 607/22.5 50} 1, 084) 21.6 
First generation..|....- do.....-| July 3-Aug. 2..| 61] 1,344] 22 33] 718/21. 8 94! 2, 062) 21.9 
Second generation.|....- do...-..| July 31-Aug. 22.| 23] 539) 23.4) 31] 714/23.03} 54) 1, 253) 23.2 
Totaltmupland, | Reee esses oes eee ae eeeoee cee 180} 3, 896] 21.7) 143)3, 184/22.33) 323] 7,080) 21.9 
cotton. 
Sea-island cotton: | 
First generation..| Cotton sq...| June 26-Aug. 4.| 92! 2,006) 21.8) 75/1, 651/22 167| 3,657) 21.9 
Long-staple cotton: 
First generation..|....- doles June 30-July 30.| 35] 726) 20.7) 26) 549/21.8 61) 1,275} 20.9 
Motalallithreeslsecs: Aa ae ece eet eee ce 307| 6,628) 21.4) 244'5,384/22.06 551/12, 012, 21.8 
types ofcotton. 
