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species of the genus Oryctes apparently have the same predilection for 
the coconut and for similar palms. ‘The presence of the rhinoceros beetle 
is indicated by the large, irregular holes in the trunks of the trees or at 
the bases of the largest petioles of the leaves of the coconut. These are 
made by the adult beetles and serve as a means of entrance for other 
insect pests, such as the Asiatic palm weevil, and also for the admission of 
moisture, which eventually causes the trunk to rot. The beetles’ attacks 
are confined to the soft tissues near the top of the tree, and holes seen in 
the trunk below this point date from the time when the growing apex 
was here located. 
No Oryctes has ever been found gnawing the hard, old wood of the 
trunk of the coconut; occasionally adult beetles are found in these old 
holes, which, however, are used only as a hiding place during the day. 
In some of them old cocoons which were constructed when the hole was 
at the crown of the tree are occasionally found, consisting of masses or 
bundles of fiber. These have been preserved in situ, because of the small 
size of the opening of the burrow. As time goes on, the old holes become 
enlarged through various agencies, particularly through erosion and decay 
caused by the entrance of water, so that these bundles of fiber finally 
become exposed. 
Life history and habits—Like all other members of the family Dynas- 
tide, Oryctes is a vegetable feeder. While it frequently occurs in heaps 
of decaying vegetation, the larve appear to have the greatest liking for 
the soft, growing point of the coconut, which is the location from which 
new leaves, the flowers, and, subsequently, the fruit, obtain their nourish- 
ment. ‘Therefore, any injury to this part of the tree immediately results 
in debilitating the whole plant and eventually in its death. The mode 
of attack most generally encountered is that in which the female has 
entered between the long stems or petioles of the outside leaves and those 
immediately subjacent, and then has eaten a hole into the outer side of 
the inner petioles, which are protected from the light by the external 
leaf stems. As this beetle shuns the light, its attacks always begin 
during the night, and by the following morning it will frequently have 
entered so far into the burrow as to be protected from the light. It 
then continues its feeding until a gallery of considerable size has been 
excavated. The habit of burrowing would seem to be not solely for the 
purpose of laying eggs but also in order to obtain nourishment, as nearly 
all of the members of this family feed in the adult stage. 
The egg.—I know of no record regarding the actual deposition of the 
egg, nor have I found it in any of the burrows from which the adult has 
been taken, but, by dissection of the females, the eggs have been obtained 
in considerable numbers. Just before being laid they are of a dark 
cream color and present a perfectly smooth texture. The microscope 
reveals a very delicate reticulation or punctuation of the surface. They 
are 3.5 millimeters long and 2 millimeters in diameter, being of a perfect. 
