492 



COLEOPTERA. 



rounded beetles of an elongate cylindrical form, truncated be- 

 fore and behind. They mine under the bark of trees, running 

 their winding galleries in every direction. They rarely attack 

 liviug healthy trees. Tlie}^ are usually brown 

 or Hack in color. The rounded head does not 

 end in a snout and is deeply sunken in the 

 thorax ; the clavate antenniB are somewhat el- 

 bowed, while the palpi are very short; the 

 elytra are often hollowed at the end, and 

 the short stout legs are toothed on the under 

 Fig. 473. gitie of the femora, and the tarsi are slender and 

 narrow. The eggs are laid in the bark, whence the larvae on 

 being hatched bore straight into the sap wood, or mine between 

 the bark and sap wood. Thc}- are like those of the })receding 

 family, fleshy, cylindrical, footless larvre, wrinkled on the back. 

 When fully grown in the autumn they gnaw 

 an exit for the beetle, taking care to leave a 

 little space closed in front of their burrow to 

 conceal tlie pupa. The bark of trees infested . 

 by them should be scraped and whitewashed. 

 ILjlurgus terebrans Oliv. (Fig. 474) is a rather 

 large red species, very abundant in spring. rig. 474. 



It is found under the bark of pines associated with Pissodes, 

 though the larva is smaller and more cylindrical. It mines the 

 inner surface of the bark, slightly grooving the sap wood, and 

 pupates in April, appearing as a beetle in great numbers on 

 warm days early in May. Hylurgiis dentatns Say 

 infests the cedar. 



The Scolytus destructor of Olivier often does much 

 injury to old and decaying elm trees in Europe. 

 Capt. Cox exhibited to the Entomological Society of 

 London a piece of elm three feet long, which was 

 scored by the lateral tubes of this insect, which he 

 estimated must ha^'e given birth to 280,000 larAie. 

 The various species of Scolytus, Tomicus and Xyloterus give 

 rise to a disease similar to fireblight, by tlieir ravages beneath 

 the twigs of fruit trees, causing the bark to shrivel and peal 

 off as if a fire had run through the orchard. The best method 

 of restraining their attacks is to peal off the affected bark, ex- 



Fig. 475. 



