16 
beetles before they enter the bark and when they emerge, while the 
larva destroys the larva and broods in the bark. 
A reil-bug enemy of bark-beetles.—A small, red to brown Hemipter- 
ous bug of the family Acanthiide and subfamily Anthocorina was. 
found inall stages of development, associated with colonies of the pine- 
destroying beetle and its allies, in the bark of recently attacked living 
and dying trees. These little relatives of the bedbug and the flower 
bugs are recognized as aggressive enemies of bark beetles, both in the 
East and West. The one found in the Black Hills is evidently P%zos- 
tethus californicus Reut. The adult is about 3 mm. long, slender, 
grayish, and exceedingly active. The young forms are usually bright 
red, active little creatures which attack and suck out the liquids from 
the bark beetles and their larve. The adult bug also attacks and 
kills the adult bark beetles. While this is a common and active enemy 
of the smaller bark beetle, it probably does not render much service 
toward checking the ravages of the destructive species. 
Other predaceous beetles.—There are also a number of predaceous 
beetles of the families Colydiide, Tenebrionide, Histeride, and 
Staphylinide which were found in greater or less numbers in the 
bark of infested trees, but their exact relation to the destructive 
beetle was not determined. 
PARASITIC INSECTS. 
Several parasites belonging to the order Hymenoptera and families 
Braconide, Chalcididee, and Proctotrupide were found to be enemies of 
the smaller bark beetle larve and adults, but none were found attack- 
ing the pine-destroying species. Therefore there does not seem to be 
much service rendered by this class of insects, which are usually so 
efficient in reducing the numbers of bark beetles. 
PARASITIC FUNGI. 
A few examples of the adults and larvee of the pine-destroying beetle 
were found which had evidently been killed by a fungus disease, but 
this was by no means common enough to have rendered any service 
in checking its ravages. 
BIRDS AS ENEMIES OF THE DESTRUCTIVE BEETLE. 
A few old dead trees and some which had been recently infested 
which showed evidence of the beneficial work of woodpeckers were 
observed in some localities, but hundreds of other insect-killed trees 
showed no trace of work by the birds. Therefore there appears to be 
very little service rendered from this source. This is evidently due 
to a scarcity of the birds and to the fact that the habit of the insect 
transforming to the adult in the inner bark makes it less accessible to 
the birds than are the spruce-destroying beetle and other bark beetles 
which undergo this change in the outer bark. 
