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the adult beetles in the trees, adding that the fact that the grubs are some- 
times found feeding in the heart of the tree high up near the crown 
makes it seem quite probable that the eggs are laid there also. Every 
evidence in my experience points to the great likelihood that they are 
laid in these holes. 
When a tree which is so badly infested as to give external signs of 
debility is cut down, one usually finds larve of all stages as well as pup. 
The question of the length of the life period of this insect is a difficult 
one to determine, but from examinations, such as it has been possible to 
make during the time the insects of coconut have been under special 
observation, I am led to believe that it varies from eighteen months to 
two years, according to the food conditions. These conditions are deter- 
mined largely by the size of the plant and the proportional number of 
insects in it. 
Pupa.—The pupa of a female measures about 50 millimeters in length and 
25 millimeters in width. The distance over the back from the tip of the head 
to the hinder part of the body, which in the pupa is curved forward, is 65 mil- 
limeters. It is of a light ocher yellow, in certain lights presenting a bright 
satin sheen and in others a velvety appearance. The head, thorax, abdominal 
segments above and below, and the wings and legs are all plainly visible, the 
anterior apex of the pupa, at a point corresponding with the top of the head 
in the adult insect, shows a small sharp knob or tubercle, which represents the 
horn of the full-grown beetle. A very fine golden pubescence, covering certain 
areas of the pupal body, causes its velvety appearance. The spiracles are placed 
similarly to those of the larva, but are almost hidden by the folds or wrinkles 
of the abdominal segments. On each side of the middle line of the back of the 
abdomen, transverse slits, very much like spiracles in appearance and undoubt- 
edly secondary breathing orifices, are seen. These occur between each two 
abdominal segments, beginning with the first and continuing to the seventh, 
inclusive. Between the seventh and eighth there is indication of their existence 
in an atrophied state. (PI. IV, fig. 2.) 
Cocoon.—The cocoon is composed of fibers of the coconut, wound transversely 
and rather compactly woven or matted together. It sometimes measures 100 
millimeters in length and 40 millimeters in diameter. When these insects live 
in rotting material or manure, the cocoon consists simply of an oval excavation, 
the interior being smoothed by the larva previous to its transformation. Unlike 
many pupe of insects which feed in the interior of masses of material, this one 
has no organs by means of which it may cut or push its way out of the cocoon 
at the moment of transformation to the adult. 
Adult.—The full-grown insect varies in length from 34 to 48 millimeters, 
according to the sex and the amount of nourishment taken in the larval stage, 
the average for the males being 44.2 millimeters and that for the females 37 
millimeters. They are of a very dark-brown, somewhat lighter beneath, and 
have a very glossy or shiny appearance. The most striking feature is the horn 
on the fore part of the top of the head, this being much larger in the male than 
in the female. The head, thorax, and abdomen are easily distinguished. (PL. IV, 
fig. 3.) 
Male——The head, with the exception of the horn, is irregular in form and 
subglobose; the front is strongly emarginate or sulcate. It is small in com- 
parison with the thorax and so concealed posteriorly by the thorax, into which 
it fits very snugly, that it appears to be subtriangular from above. The eyes 
