16 BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. 
normally, merely being weighted by a light string tag. When the 
infested squares fell the date was recorded on the tag. All of the 
infested squares of a certain weevil were assembled in an inclosed 
area to prevent damage (fig. 7) and placed on the soil under the 
plant just as they would normally lie. They were watched daily, 
and only about two 
days before emergence 
was expected were 
covered, still under 
the plant, by coarse 
wire screen cages (fig. 
7) in order to get the 
number of weevils 
that emerged and 
determine the sex. 
Hence abnormal con- 
ditions were experi- 
enced for only about 
2 days. 
Since these records 
indicated a much 
longer developmental 
period than was re- 
corded in previous 
bulletins, a complete 
series of control ex- 
periments was con- 
ducted in the outdoor 
insectary (fig. 8). 
: Se Ses It will be seen by 
Fic. 6.—The infested squares tagged on the cotton plant, Table Vill that the 
2] ae - developmental period 
in the tumblers under insectary conditions at Madison is much more 
rapid than under the most favorable outdoor conditions experienced. 
TaBLeE VIII.—Showing the length of the developmental period of the boll 
weevil under insectary and field conditions, Madison, Fla., 1918. 
In insectary, developmental Outdoors, normal develop- | Aver- 
period. mental period. | age. 
Ten-day oviposition period. ieee Days. eed Days. | Accel- 
ber of | ber of eration 
weevils Vils | of in- 
bred, | Maxi- | Mini- | Aver- bak Maxi- | Mini- | Aver- | sectary 
mum, | mum. age mum, | mum, | age. | days. 
ee, 
sono 4-139 ~ oe a ee 370 15.6 13.6 14.8 | 50 24.5 20.1 21. 6.8 
Joly S15 20 2 eee es 306 15.2 13.7 14.5 94 24.2 20.8 21.9 | 7.4 
Soly si—Ane 9. as ee S71, 18 14.8} 15.8 | B41. 243.1 39. 6:) ase 7.4 
