THE INSECT WORLD. 



207 



Phymatodes amcenus : pupa and adult. 



sometimes killed, an old cherry-tree, fully eighteen inches in 

 trunk diameter, which died rather suddenly, having the roots 

 absolutely riddled in every direction by a dozen or more of these 

 immense creatures. 



The species of Phymatodes are much smaller, a little flattened, 

 with an oval thorax and a tendency to blue and yellow colors. 

 The larvae feed only in dead or 

 dying wood : P. amoenus, a bright 

 blue species w4th yellow thorax, 

 attacking dead shoots of grape, 

 while P. varius and P. variabilis 

 live under the bark of oak cord- 

 wood. The beetles appear in 

 spring and lay their eggs in 

 dying wood or in wood cut 

 during the winter, often in such 

 numbers that the bark is com- 

 pletely loosened by the larvae and will, next spring, slip off in 

 its entirety. They are hence called "bark-slippers" by wood- 

 men. In the Southern States they infest tan-bark, sometimes 

 injuring it considerably. Cutting the tree? during the summer, 

 after the beetles have disappeared, or very early in fall will put 

 the bark and wood in such condition that it will not be attractive 

 the season next following. 



The species of Elaphidion are narrow, brown beetles, covered 

 with whitish, somewhat mot- 

 tled pubescence, and have long 

 and rather stout antennae. 

 They are known as ' ' oak- 

 pruners," because the larvae 

 of several species bore into 

 twigs and branches of oak and, 

 when nearly full grown, girdle 

 them from the inside, so that 

 the first high wind of early 

 winter breaks them off, carry- 

 ing the larvae to the ground. 

 Transformation is completed in the June or July following. Often, 

 during late summer, the wilting of a twig or small branch indi- 



FlG 



The oak-pruner, Elaphidion parallelum, 

 —a, larva ; b, pupa in its burrow ; c, beetle ; 

 kk, cut ends of the twig ; d to i, structural 

 details. 



