Plate IX. 
Fic. 27. Burrows of Chrysobothris dentipes in white 
pine. The greater part of the larval burrow of this species 
is in the sapwood immediately under the bark. When nearly 
full grown the larva tunnels into the wood and often bores 
through this for a distance of several inches before pupating. 
In emerging the adult makes an opening of its own which is 
often at some distance from the point at which the larva 
entered the wood. Reduced to slightly less than three-fifths 
natural size. 
Fic. 28. Section of the trunk of larch showing the burrows 
of Polygraphus rufipennis (upper left) and of Hccoptogaster 
picee (right) and the exit holes of Urocerus albicornis. 
Reduced to about two-thirds natural size. 
Fic. 29. View of a segment of the trunk of Tree V. The 
exposed decaying wood was killed a number of years ago, 
probably by peeling. At that time it had been tunneled by 
the larvee of Serropalpus barbatus and perhaps other forms, 
and decay had for this reason been more rapid. A specimen 
of Adelocera brevicornis was taken from this wood in the 
field, and Tenebrio tenebriodes and Dryophthorus ameri- 
canus were bred from it in the breeding cages. The more 
recently killed wood at the sides shows the engravings of 
P. rufipennis. Reduced to one-third natural size. 
Fig. 30. Portion of the heart wood from Tree V, showing 
the larval burrows made by Serropalpus barbatus many years 
before. The burrows of Dryophthorus americanus may be 
seen at various places. This insect bores in the soft “ spring 
wood,” leaving the harder “ summer wood” nearly intact. 
Reduced to about two-thirds natural size. 
