16 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
4, THE APPLE FLAT-HEADED BORER. 
Chrysobothris femorata Fabricius. 
Order COLEOPTERA; Family BUPRESTID.®. 
Boring under the bark and in the sap-wood of the white oak, and in the Gulf States, 
the pin oak; a pale-yellow flat-headed grub, closely resembling the preceding species 
This pernicious borer of the apple tree, as stated both by Harris and 
Fitch, originally infested the white oak, but since the settlement of the 
country has abounded in the apple and sometimes in the peach, though 
it may still be found to injure the white oak. 
Fig. 3 will fairly represent the “ mine” or gallery made under the bark 
of a stump of the white oak, as it occurred at Providence, Rk. 1. The 
worm soon after hatching made the mine as is seen on the right of the 
figure, where after a sinuous course it opens into a broad shallow cell, 
and then after pursuing an irregular direction dilates on the left into a 
broad shallow cell two-thirds of an inch wide, the oval black spot in 
the upper right corner representing the hole made by the larva for the 
exit of the beetle. In this hole the beetle was found. The large cell is 
for the repose of the pupa. 
At Houston, Texas, I found the larva and pupa in abundance, April 
2, 1881, under the bark of large pin oak stumps, and of dead trees. The 
burrows were like those represented in Fig. 3, being irregular winding 
shallow burrows, not nearly so definite in outline as those made by 
longicorn borers. The mine is about + inch wide, and terminates in a 
broad irregular oval cell 14 inches long and 4 to 3 inch wide. In this 
cell the pupa spends the winter and early spring. One end of this cell 
lies toward the outer side of the bark, so that even if there is not a 
clearly defined oval opening as in Fig. 3, the beetle on emerging from 
the pupa state can with little difficulty extricate itself from its cell and 
make its way out of doors by pushing aside a thin barrier of bark. In 
the case of one mine in the pin oak there was a quite regular oval cell 
built up by the larva between the wood and the bark, the partition con- 
sisting of a composition of fine bark dust, thus forming a rude cocoon, 
The insect occurred at Providence in the larva, pupa, and beetle states 
May 20, though the farvie were the most abundant. 
Harris says of it from his observations in Eastern Massachusetts: 
Its time of appearance is from the end of May to the middle of July, during which 
it may often be seen, in the middle of the day, resting upon or flying round the trunks 
of white-oak trees and recently-cut timber of the same kind of wood. I have re- 
peatedly taken it upon and under the bark of peach trees also. The grubs or laryie 
bore into the trunks of these trees. 
The following extracts from Dr. Fitch’s first report will further serve 
to characterize the habits and appearance of this formidable pest of our 
most valuable forest, shade, and fruit trees. It will appear that Dr. 
Fitch has been the first to discover an ichneumon parasite in the larva 
