1G4 
HALF HOURS WITH INSECTS. [Packard. 
white bark beneath, as can easily be done without any injury 
to the tree, wherever there is a young worm it can easily be 
detected. A little blackish spot, rather larger than a kernel 
of wheat, will be discovered wherever an egg has been de¬ 
posited, and by cutting slightly into the bark the worm will 
be found. It gradually works its way onwards through the 
bark, increasing in size as it advances, until it reaches the 
sap-wood ; here it takes up its abode, feeding upon and con¬ 
suming the soft wood, hereby forming a smooth, round, flat 
cavity, the size of a dollar or larger, immediately under the 
bark. It keeps its burrow clean by pushing its excrement 
out of a small crevice or opening through the bark, which it 
Fig. 129. 
Apple Tree Borer. 
makes at the lower part of its burrow, and if this orifice 
becomes clogged up it opens another. This excrement 
resembles new fine sawdust, and enables us readily to de¬ 
tect the presence of the worm by the little heap of this 
substance which is accumulated on the ground, commonly 
covering the hole out of which it is extruded, and by par¬ 
ticles of it which adhere around the orifice when it is higher 
up, or in the fork of the tree ; the outer surface of the bark 
also often becomes slightly depressed, or flattened, over this 
cavity.” 
When half grown it sinks into the solid heart wood of the 
tree and obliterates the flat cell, filling it up with its casting 
4 
