254 



WEST VIRGINIA EXPERIMENT STATION. 



illustration.) it is exceedingly common in the bark of white 

 pine, and attacks all of the other kinds of pine in the State. I 

 have also found it in both the Norway and black spruce of the 

 State, but not so common as in the pine. In May and June, 

 1897, I-found it quite common excavating egg galleries in the 

 living bark of black spruce in the pine swamps near Cranes- 

 ville, Preston county, and my observations of its habits led me 

 to conclude that under favorable conditions, it might prove a 

 destructive enemy of the spruce. 



FLAT-HEADED SPRUCE BAKK MINERS. 



The so-called ^flat-headed" bark miners are white, footless 

 grubs, wiih the front segments of the body broad and flat, the 



first segment resembling the head. 

 The real head is comparatively 

 small, but armed with stout, biting 

 mandibles, by means of which they 

 burrow in the bark and wood. The 

 portion of the body back of the first 

 two or three segments is usually 

 quite slender. 



These grubs hatch from eggs de- 

 posited in the outer and inner bark 

 by beetles, like Fig. XXVI. They 

 burrow through the inner -layers of 

 bark and outer layers of the wood, 

 until they attain their full growth, 

 when they excavate cavities either 

 in the outer bark or in the wood in 

 which they transform to adults. 

 I have found several species on or in the spruce, and have 

 observed numerous forms and sizes of the grubs in the bark of 

 spruce trees and twigs which could not be identified. There are, 

 doubtless, quite a number of species of this class of borers which 

 infest the spruce. I have found some of these larvae in the 

 living bark of standing and felled trees, and have other evi- 

 dence which leads me to believe that they might, under favor- 



Fig. XXVI. Flat headed Wood 



Miner, a larva, b adult, 



(the latter after Marx.) 



