June 4,1917 
The Pink Bollworm 
345 
It has not been possible to ascertain how widely distributed the pest 
has become in Mexico beyond the Laguna district near San Pedro, where 
it is already a serious pest, but its presence there constitutes a very grave 
menace to our cotton fields. When it is considered that the introduction 
of this insect into American cotton fields would mean a permanent annual 
loss of millions of dollars to the United States, it becomes evident that 
all possible precautions should be taken to prevent or delay its arrival. 
An essential step toward this end is a thorough knowledge of the 
insect in all its stages which will enable its prompt recognition in any 
stage, even from fragments, by the agents employed to prevent its intro¬ 
duction. The detailed description given in this paper provides this means 
of identification. It is based on an investigation of its life history and 
habits, conducted in the Hawaiian Islands during the summer of 1915 
and subsequent anatomical studies made from material from various 
sources. 
There is added to the paper a similar detailed descriptive and anatom¬ 
ical study of another lepidopterous insect, Pyroderces rileyi Walsingham, 
which may be called the “scavenger bollworm” because it frequently 
occurs in decayed or dried bolls injured by other insects. It seems de¬ 
sirable to include this supplemental study of Pyroderces rileyi , which 
frequently has been and may be mistaken for the pink bollworm. The 
anatomical details given in this paper will make it possible for the 
inspector to distinguish readily these two insects. 
ORIGINAL HOME AND PRESENT RANGE 
Although the species was first noticed and described from India, it is 
not probable that India is its original home. 
Saunders expressed the belief, in his description of the species (1, 2), 
that the pink bollworm was imported into India with American cotton, 
which it preferred to the Indian varieties of Gossypium. If so introduced 
into India it was probably with the seed of some American variety of 
cotton grown in some part of Africa. Oj:her early East Indian records 
have been traced by Durrant (26) to Egyptian cottonseed, and Africa 
is, from all the evidence on hand, apparently the original home of P. 
gossypiella. The occurrence there as well as in southern Europe of the 
only other known species (P. malvella Zeller) of the genus Pectinophora 
is in itself a strong support for the theory of African origin. 
The species has spread to most, if not all, the cotton districts in Africa, 
Asia, Japan, Ceylon, Straits Settlements, Philippines, and Hawaiian 
Islands; and within the last few years it has been brought to the American 
continent and is already established in Brazil and Mexico (3, 4, 13, 14, 15, 
20, 21, 22, 23, 25, 26). 
* This nearly cosmopolitan distribution leaves the United States prac¬ 
tically the only large cotton-producing country free from the pest, and 
