6 BULLETIN 1374, U. S. DEPARTMENT OF AGRICULTURE 
The great number of punctures counted on the bolls is very striking. 
These particular bolls were not examined further to determine the 
number of larvae inside, but three field examinations made on October 
5, 13, and 20, respectively, gave an average of 5.64 larvae and exit 
holes per boll. So it may be assumed that the infestation of the bolls 
on which Table 2 is based was somewhere near this figure. 
In some cases the young larva goes directly through the entire wall 
of the boll and into the lock of cotton inside. In this case the point 
where it passed through the inner wall is only slightly raised and may 
be somewhat colored. Very frequently, after passing through the 
greater part of the wall of the boll, it tunnels for some distance just 
underneath the inner surface of the wall. In this case the t unn el 
usually extends until either the suture or the partition wall is reached, 
at which point the larva then enters the lock. This tunneling occurs 
more commonly in nearly mature bolls, where the inner wall is 
harder. Some of these types of entrances are shown in Figure 3. 
ISSUANCE OF FULLY DEVELOPED LARVAE FROM BOLLS 
In the fall of 1922, a test was conducted in the laboratory to 
determine the time of the day mature larvae leave the green bolls. 
Fifty green bolls were placed in a screen-bottom tray, with a trap 
underneath to catch any emerging larvae. All larvae were removed 
from the trap each day at 8 a. m. and at 8 p. m. Of 172 larvae taken 
out of the trap from September 29 to October 17, 160 were removed 
in the afternoon and 12 in the morning. According to this, the 
larvae, at least under laboratory conditions, prefer to leave the bolls 
during the daytime. 
TRANSFORMATION AND HIBERNATION OF THE PINK BOLLWORM IN THE SODL 
PUPATION DURING SUMMER 
In the Laguna district the pink bollworm passes the pupa stage 
during the summer in shed blooms and bolls, under or attached to 
leaves on the surface of the soil, and in the soil. Rarely are pupae 
found in bolls on the stalks. None were ever found in green bolls. 
One hundred and seventy-four open bolls on stalks examined during 
the period from July 7 to November 28, 1921, showed neither pupae 
nor pupal cases, but a total of 358 larvae and exit holes. The last 
figure, however, does not represent the total infestation, since larvae 
issuing from the bolls after opening do not as a rule cut exit holes 
through the wall. Open bolls on stalks during the latter part of 
November and in December, 1922, averaged about 8 pupae and pupal 
cases per hundred. 
VARIATIONS IN NUMBERS IN THE SOIL 
A considerable number of field examinations were made during 
1921 and 1922 in a study of the transformation of the pink bollworm 
in the soil. In making these examinations, samples of soil, usually 
1 square yard to the depth of 6 inches, were taken from heavily 
infested cotton fields and the number of pink bollworms in each 
sample determined. The square yard was laid off so as to have a 
row of cotton running through its middle. The soil was first sifted 
through a sieve of which the mesh was too small to allow the passage 
of pink bollworms. The coarse remaining material was taken to the 
laboratory and washed through other sieves, leaving finally only 
