June 4, 1917 
The Pink Bollworm 
35i 
Pupa. —The pupa (Pl. 12, A-D) is 8 to 10 mm. long, rather plump, reddish brown; 
posterior end pointed and terminating in a short, stout, upwardly turned hooklike 
cremaster; entire surface finely pubescent; no long setae, spines or hooks, except on 
last joint; fronto-clypeal suture distinct and curved sharply upward; clypeus, labrum, 
pupal eyes and mandibles distinctly indicated; antennae diverging at their extreme 
tip and not reaching to the tips of the wings; metathoracic legs reaching slightly beyond 
the wings to fifth abdominal segment. Spiracles small, normal. Anal opening large, 
slitlike, surrounded by strong hooked setae, 5 or 6 on each side; cremaster surrounded 
with 6 to 8 similar, strong, hooked setae. Genital opening slitlike, single in both 
se^es. When mature, the pupa becomes much darker (PI. 12, C); the imago’s eyes 
can be seen prominently under the gena of the pupal skin, and the segmentation of 
the adult antennae and legs becomes discernible. 1 
Egg. —Elongate oval, flattened; about 1 mm. long and 0.5 mm. broad; the shell 
is pearly white, with a finely wrinkled surface. 2 When, newly laid, the egg has a 
slightly greenish tint. At maturity it turns reddish. 
SEASONAL HISTORY AND NUMBER OF GENERATIONS 3 
The small eggs are difficult to detect without the aid of a lens. They 
are laid singly or in small groups on 
any part of the green cotton boll or 
its calyx or even in the flower, but 
are by far most commonly found 
near the apex of the green boll in 
the slight longitudinal depressions 
which indicate its divisions (fig. 3, a). 
From 1 to 4 eggs are commonly seen, 
and sometimes as many as 20 may 
be found on a single boll, probably 
laid by several females. The num¬ 
ber of eggs laid by a single female 
is difficult to ascertain in nature, but 
dissections prove that each female 
is capable of laying more than 100 eggs. The egg hatches in from 4 to 12 
days after it is laid. 
The larva when first hatched is very small, glassy white, with light- 
brown head and thoracic shield. It tunnels into the boll under the egg¬ 
shell or near by and feeds in the beginning on the soft inner walls or in 
the equally soft partitions separating the divisions of the boll. The 
larva is easily overlooked at this stage when the boll is opened and 
1 The terminology of the pupa has been adopted from Miss Edna Mosher’s valuable paper: (Mosher, 
Edna. A classification of the Lepidoptera based on Characters of the pupa. In Bui. Ill. State Lab. Nat. 
Hist., v. 12, art. 2, p. 17-159, pl* 19-27* 1916.) 
2 The egg has been described by Fullaway (16, p. 18, fig. 10) as having “a peculiar sculpturing of the sur¬ 
face, which renders them unmistakable when observed with a hand lens,” and his figure shows a regular 
cross-line effect, but there is no such true sculpture of the egg surface. When laid, the egg is soft and smooth 
and the surface merely becomes irregularly wrinkled shortly after it is laid. 
8 The biological observations on which this paper is based were made by the writer in 1915 in Honololu, 
T. H.; but they coincide with the results of other students of the insect in other parts of the world, and the 
data will undoubtedly hold true, with slight modifications, in the United States, if the pest becomes estab¬ 
lished here. 
Fig. 3.— Cotton boll infested with Pectinophora 
gossypiella a, Eggs in situ ; b, exit hole of moth. 
(Original.) 
