12 
BULLETIN 723, U. S. DEPARTMENT OF AGRICULTURE. 
The eggs are laid singly or in small groups on the green bolls or 
in the flowers. Generally the eggs are to be found near the points of 
the green bolls in the sutures marking the locks. As many as 4 
eggs may be found in this situation and altogether as many as 20 
eggs have been found on a single boll. It is estimated that a female 
will deposit in the neighborhood of 100 eggs. These hatch in from 
4 to 12 days. 
The larva, immediately on hatching, bores its way into the boll.' 
The infested bolls sometimes become recognizable by a reddish or 
blackened discoloration which follows attack. Mr. Busck finds, 
however, that the only conclusive ex- 
terior evidence of infestation is the 
eggshell at the entrance hole or the 
larva itself within the boll. 
The food of the larva is the seed 
within the boll. It devours one and 
generally proceeds to the next above. 
Ordinarily a single larva does not 
make its way outside of the lock 
which it first invades, but occasion- 
ally the adjoining lock may be en- 
tered. It is to be noted that the 
larva restricts itself to the .interior 
of the boll and never makes its way 
to the outside for the purpose of 
reaching another boll. When the 
larva reaches full growth it often 
protects itself by webbing two seeds 
together, the attachment being made 
to openings brought into contact by 
the insect. These " double seeds " are characteristic of the work of 
the insect. Usually they are not destroyed in the process of ginning, 
and they furnish the best means of determining quickly whether any 
lot of seeds is infested. 
During the summer the larva stage occupies from 20 to 30 days. 
Later in the season this stage may be more or less indefinitely pro- 
longed. Gough (6), in Egypt, found that larvae would remain in a 
quiescent condition for over two years. Mr. Busck caused infested 
seeds to be placed in small bales of cotton in Honolulu. Examina- 
tions made up to 18 months after the time of baling continued to 
reveal the presence of live larva?. It is thus evident that the larva 
stage may be prolonged over at least two growing seasons. It is this 
feature in the life history of the pest which has facilitated its car- 
riage to many remote quarters of the earth. 
"ig. y. — Pink bollworm on carpel of 
cotton boll, which shows also typical 
hole made by worm while travel- 
ing from one lock to the next. 
