29 
BULLETIN 91$, U. S. DEPARTMENT OF AGEICLLTLEE. 
turbed by other insects, such as the flower beetle, Euphoria hasalis 
Gorg. If the larva is not full-fed at the time of opening it niay 
continue feeding inside the flower for two or three days or until 
after the flower has dropped, or it may work downward from the 
flower into the newly formed boll. Xo indication of the larva leav- 
ing flowers and going into large bolls was ever observed, and it is 
exceptionally rare to find more than one larva in a single square or 
flower. From June 1 till August 10, 1919. a daily record, with a few 
exceptions, was kept of the flowers opening on a small plot of heavily 
infested cotton at Ciudad Lerdo. The results are given in Table X. 
Table X. — Infestation of cotton blossoms by the pink boUicorm. 
M :•-:;-_. 
Number 
of 
days 
counted. 
£El TotaL 
Percent- 
age 
infested. 
June ' 25 
July 25 
August 10 
226 
898 
967 
S,210 
12,333 
2,508 
13,231 
3,475 
27. S 
On October 3. 50 per cent and on Xovember 10. 90 percent of the 
flowers on this same plot were infested. This plot was more heavily 
infested than is normally the case under field conditions. The in- 
festation is usually highest in June and July, when few large bolls 
are present on the plants, and decreases during August and Septem- 
ber. In October and Xovember. when there are many larva? pres- 
ent and not so many green bolls, the infestation again increases and 
the few blossoms appearing at this time are heavily infested. As 
the feeding in the squares and blossoms is largely on the pollen, 
the presence of a larva does not necessarily prevent a normal boll 
from forming. Blossoms were tagged in 1919 and it was found 
that 40. S per cent of the noninfested squares and 67.6 per cent of 
the infested blossoms were shed. 
LARY.i FEEDING EN" BOLLS. 
That inside the bolls is the most favored feeding place for pink 
bollworms is shown by the fact that as soon as the bolls are large 
enough most of the larvae choose bolls instead of squares or flowers. 
They attack the boll in all stages of its growth, from the time it is 
the size of a pea until it begins to open, though most commonly 
it is not entered until about one-half to three-fourths grown. The 
larva? bore into the boll at any point upon its surface soon after 
hatching and remain in the same boll until ready for pupation. 
Once the larva? have entered the boll no definite plan of procedure 
is followed. They may burrow directly through the carpel and 
begin feeding on the soft watery lint or they may stop before cutting 
completely through and burrow for an inch or more in the spongy 
