INSECTS AFFHCTIN'C I'AUK AND WOODLAND TREES 



59 



Maple and oak twig pruner 



Elaphidion villosit))i Fabr. 

 Small, cleanly cut twigs of oak or maple falling during the summer are signs of this 

 insect's work. 



This insect probab'y attracts more attention than any other species 

 causinj^ the same amount of damage. As a general rule it is not very inju- 

 rious, except possibly to shade trees on lawns and along roadsides where 

 s)'mmetry and beauty are very desirable. Aside from damage to the trees, 

 the falling twigs are a source of annoyance and form the one sign of the 

 insect's presence most commonly noted. 



Description. This species, like some others, is most easily recognized 

 in connection with its work. A fallen twig is found to have its larger end 

 nearly eaten off, as represented on plate 2, the cutting being nearly as 

 smooth as that of a sharp chisel. The central burrow is plugged with .saw- 

 dust and if the twig be whittled, a large proportion of its interior will be 

 found eaten away and somewhere in the burrow there is usually a whitish 

 grub with brown jaws [pi. 2, fig. 7], our carpenter. The beetle is a rather 

 slender, grayish brown insect [pi. 2, fig. 9]. 



Life history and habits. The adult is said to deposit an ^^^ in July 

 in one of the smaller twigs. The young larva feeds for a time on the 

 softer tissues under the bark, packing its burrow with castings and working 

 toward the base of the twig. Later it bores along the center of the limb, 

 making a more or less oval channel. In the early fall our borer quietly eats 

 away a large portion of the woody fiber, plugs the end of its burrow with 

 castings and waits for a high wind to break of¥ the nearly severed branch. 

 In this manner the larva reaches the ground in safety. Late in the fall or 

 in the early spring the change to the pupa takes place and the transforma- 

 tion to the perfect insect occurs in the spring, the beetles emerging from 

 the limbs in June and continuing abroad till September. Occasionally the 

 insect completes its changes in the portion of the limb remaiiiing on the 

 tree ; it as a rule drops with the severed branch. 



The reason for cutting off the limbs has been accounted for in different 



