232 HALP HOURS WITH INSECTS. [Packard. 



clothed with the short, stiff hairs which cover their bodies, 

 pass backwards and forwards in their burrow, they brush the 

 dust and chips into the notches, thus covering the eggs up. 



When they hatch the young grubs gnaw their way straight 

 out for two or three inches from the primary tunnel, which 

 may be from four to eight inches in length. It has been 

 noticed that the burrows are alwa3^s separate, never touching 

 or crossing each other. When about to pupate, i. e., change 

 to a pupa, the grub sinks deep into the wood at the outer 

 end of the burrow. This species attacks the pine wdien in 

 perfect health. 



Another wood engraver, nearly two lines in length, is the 

 Tomicus cdlligraphus. It makes short, large, irregular bur- 

 rows, and is common in the yellow pines of the Carolinas, as 

 well as the pitch pine of the northern states. 



The burrow of the Tomicus pini is like a bird's claw, or 

 the fingers of a hand. As the beetle is a line and a half in 

 -PiQ, 170. length its burrows are rather 



II I I f I I f I I'^^-i'sf^i' than usual. 



"" i i The smallest form known is 



Tunnel of Timber Beetle. ^^^^ TomicuS pusillus, slightly 



more than half a line in length. 

 It mines extremely fine, slender, wavy passages in every di- 

 rection, mostly in the wood. The eggs are laid so that the 

 3^oung grubs mine outwards, travelling awaj^ from each other. 



In the bark beetles there are several males to one female 

 at work in a mine. We now come to the true timber beetles, 

 which sink their tunnels deep into the wood. Here the fe- 

 males are most numerous, and are probably not aided in 

 their work by the males. 



The Tomicus materarius is aline and a half long, and red- 

 dish-3^ellow in color. It makes a straight burrow, with regu- 

 lar secondary tunnels running out at right angles to the main 

 one, somewhat as in Fig. 176. Its presence may be known 

 by the clean white piles of borings it throws out of its hole. 



