BEETLES. 



333 



The species of Prionus have three teeth upon each side of the prothorax, the 

 antennae are imbricated ; in P. imbricornis the imbrication is beautifully exhibited. 

 The antennae have, in American species of Prionus, from twelve to twenty-seven 

 joints. P. laticollis, one of the common North American species, is from 0.75 to 1 

 inch in length, brownish black in color, and both male and female have twelve-jointed 

 antennae. In P. imbricornis the joints of the antennae of the male vary from eighteen 





18 



FIG. 3T3. a, Prionus coriarius, and b, Ergatis faber. 



to twenty, while those of the female have from sixteen to seventeen joints. The 

 males sometimes have a different number of joints in the right and left antennae. The 

 fleshy white larvae of P. laticollis bore in the roots of various plants, among which 

 may be especially mentioned grape, apple, poplar, and pine. In Europe, P. coriarius 

 is the common species ; its larva feeds in the wood of 

 oak, birch, beech, and pine. Its eggs, which are de- 

 posited, two to eight or more in the same place, are fusi- 

 form cylindrical, from 0.16 to 0.20 of an inch long, and 

 0.04 to 0.05 of an inch in diameter. The eggs hatch 

 in about thirty-seven days, the young larvae eating 

 the bark of the tree on which the eggs are laid. 



Orthosoma brunneum (sometimes called O. cylin- 

 dricum}, a more elongated species than those of 

 Prionus, is found in the eastern United States. It 

 is from 1.25 to 1.75 inches long, of light-brown color, 

 and has eleven-jointed antennas. Its large fleshy 

 larva, which resembles that of Prionus, bores in 

 rotten stumps of pine, oak, and hemlock. 



A large pitch-brown European species of Prioninse, Er gates faber, from 1.25 to 2 

 inches long, feeds, in the larval state, upon pine wood. 



FIG. 374. Orthosoma brunneum. 



