OAK-BORERS. 



65 



Fig, 



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 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, Tex., 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. 18, 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, irreg- 

 ular, oval cell 1^ inches long and ^ to § 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. 18, 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 in the pin oak there was a 

 quite irregular, oval cell built up by the larva 

 between the wood and the bark, the partition 

 consisting of a composition of firm bark dust, 

 thus forming a rude cocoon. The insect occurred at Providence in 

 the larva, pupa, and beetle states May 20, though the larvae 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 larvae 

 bore into the trunks of these trees. 



Mr. Ricksecker remarks that on the Pacific coast it "attacks young 

 fruit trees that have been scorched by the sun, but its natural food is 

 the oak, for I have seen dozens of them in the branches of a small live 

 oak that had been cut down less than an hour." (Ent. Amer., i, 97.) 



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 

 of this beetle, no European Buprestid beetle being, so far as we know, 

 infested by internal parasites: 



Another insect, which has not heretofore been noticed in our country as a borer in 

 the apple tree, pertains to the family Bupreatidce, or the brilliant snapping beetles. 

 5 ENT 5 



17. — Transformation of 

 Chrysobnthris femorata. — 

 a, larva; 6, pupa ; c, under side 

 of the head and thorage seg- 

 ments ; d, beetle. After Riley. 



