6 
BULLETIN 13f)7, IT. S. DEPARTMENT OE AGTUCUT/I 'URE 
a somewhat pinkish color. It may be distinguished from the pink 
bollworm by its habits, especially by the fact that it does not feed 
altogether in the interior of the bolls and that it is not found 
within the seeds. When full grown it is much larger than the 
pink bollworm, measuring about 2 inches in length. 
There is also an*insect which feeds in plants known as "nigger 
heads" {Rudbeckia spp.), and another feeding in cat-tails (Typha 
spp.), both of which are sometimes mistaken for the pink bollworm 
(i£, pp. 813, 831). The latter is especially confusing, as it is often 
found in cotton bolls late in the season. 
The insect most likely to be mistaken for the pink bollworm is the 
boll weevil. Although the boll weevil is sometimes found in seeds, 
it generally is found feeding within the interior of the boll. It 
discolors the fiber considerably, and this causes the 
interior of the boll to assume a more or less decayed 
appearance, quite unlike the appearance of bolls in- 
fested by the pink bollworm, in which decay gen- 
erally does not occur. This so-called cleanliness of 
the work of the pink bolhoorm is one of the most 
useful characteristics in differentiation. 
The accompanying illustrations will assist the 
reader in deciding whether the work in question is 
that of the pink bollworm or some other insect 
found in cotton bolls. 
Figure 4 shows on the left the appearance of 
the interior of an injured boll, and on the right 
the characteristic small circular opening made by 
the larva in leaving the boll or for the purpose of 
allowing the adult to emerge. 
Figure 5 shows on the left the characteristic 
opening made by the ordinary bollworm (Chloridea 
obsoleta). It is of large size and surrounded by 
a raised margin. The exit holes of the pink boll- 
worm, shown on the right, are much smaller, more 
regular, and without raised margins. 
Figure 6 shows the appearance of locks of cotton 
li'usci- enlargedi bearing the typical injury caused by the pink boll- 
worm. 
Figure 7 shows individual seeds infested by the pink bollworm. 
In the lower line are the " double seeds." These are frequently found 
as the result of the webbing together of two seeds by larva 1 of the 
later stages in order to obtain more room for pupation. 
Figures 8 and 9 illustrate the pink bollworm in a burr and the 
typical opening made by this insect when it makes its way from one 
lock to another. 
Although these descriptions may help in enabling anyone to deter- 
mine whether the pink bollworm is present in a cotton field, if w4m 
always be best to send any specimens to an entomologist for authori- 
tative determination. It is extremely important that any possible 
infestation by this insect be brought to attention at the earliest pos- 
sible date, that prompt eradicative measures may be taken. 
Under the authority of the Federal Horticultural Board, August 
Busck spent a number of months in the Hawaiian Islands in 1915 
Fig. 3. — The pink 
