June 4, 1917 
The Pink Bollworm 
353 
The larval stage from the hatching of the egg to the spinning of the 
cocoon occupies from 20 to 30 days during the summer. During the 
colder months, or under abnormal, dry conditions, the larval period may 
be much prolonged. The species overwinters as larva within the seeds. 
The larva normally makes its cocoon and pupates within the boll, 
partly within the last seed attacked. Before finishing the cocoon the 
larva gnaws a round hole through the outer wall of the boll to insure 
free exit for the issuing moth (fig. 3, b). It has an evident preference 
for a firm cover for its cocoon and a firm support for the imago to issue 
from. The cocoon is always spun next to the shell of the boll, and the 
exit hole is invariably gnawed through the shell, which at that time is 
often woody and hard, although an easier and more abundant exit sur¬ 
face could be found in all other directions through the loose lint of the 
boll, which by this time has opened. 
The cocoon consists of a single thin, but rather tough, layer of dirty- 
brown silk. If disturbed at the time of maturity the larva may leave 
the boll, fall to the ground, and spin its cocoon an inch or more down 
in the soil or in any convenient shelter under a stone or among brush 
and leaves and will successfully finish its transformation. Under nor¬ 
mal conditions in the field, however, the pupation nearly always takes 
place within the boll. 
The pupal period lasts from 10 to 20 days. The empty pupal shell 
remains within the cocoon when the moth issues. 
The imago is a small, inconspicuous, sluggish moth, rarely seen in 
nature, because it hides away during the day, mostly on the ground 
under stones or in brush, sometimes actually burrowing into the surface 
of the soil. The time of flight is from 6.30 to 8 p. m.; but, though the 
moths have ample wings for a strong, sustaining flight, they fly only to 
the nearest cotton bolls for copulation and egg laying, which under nor¬ 
mal conditions takes place soon after issue. 
The moths die shortly after opposition. Under most favorable condi¬ 
tions, in a cool place supplied with water, some moths were kept alive 
for 32 days, but the majority died even under these conditions in from 
14 to 20 days. 
The entire life from the laying of the egg to the next egg laying may 
be accomplished under favorable conditions in 35 days, but 40 to 50 
days is the more common period even in midsummer, and in the colder 
months the life cycle may extend over three or four months. Thus, four 
or five or even six overlapping generations may be produced in a year. 
The winter is passed in the larva stage in the seed. 
The writer's observations in Honolulu in 1915 began on May 18. At 
that date the insect was found in all stages; eggs, larvae, and pupae were 
obtained in the field, and one moth issued from one of the collected 
pupae the following morning. About 50 per cent of the green bolls were 
infested at this date. 
