20 LARViE OF THE PEIONIN^. 



It has been found associated with imbricornis in chestnut, in chest- 

 nut roots, and probably has similar habits. It occurs throughout 

 the eastern and central United States. 



Prionus californicus Mots. 



Epistoma projecting over ctypeus for its entire width, farther at 

 extremities, narrowing in middle into two blunt teeth, although 

 rarely not dentate; front produced over epistoma into a broad, 

 straight, undivided, dull carina; mandibles very coarsely rugose 

 on outer face, molar portion toothed, not striate. Labrum trans- 

 versely oval, about one and one-haK times as wide as long. Other- 

 wise similar to imbricornis. 



Pleural discs very finely radially striate, distinct on six abdominal 

 segments; spiracles broadly oval; dorsal anal lobe slightly larger. 

 Form tapering, texture shining. 



This insect, hke the eastern species, is a serious pest to oaks. - The 

 writer has observed its work on the Oregon oak. Mr. B. T. Harvey, 

 of this office, reports it as causing death, stag top, and stunted and 

 distorted growth in Cahfornia black oak, Garry white oak, western 

 Cottonwood, western white alder, and madrona. It is most abun- 

 dant in Cahfornia black oak. Mr. Harvey further states that the 

 young larvae bore into the bark at the base of the tree and when 

 about an inch long penetrate the roots. The mines are packed with 

 sawdust and sand. Trees on hillsides and in thin soil are much 

 more frequently attacked than those in other situations. The adult 

 flies from July to August. 



Prionus pocularis Dalm. 



Epistoma as in laticolUs, but sharply edged and longitudinally 

 wrinkled or striate; labrum transversely oval, not twice as wide as 

 long, hairs extending behind middle; last joint of maxiUary palpi 

 conical, as long as second is wide; hairs on lacinia and palpi not so 

 dense as in imhricornis and much coarser, subulate. 



Prothorax mth a very dark ochraceous, conspicuous band on ante- 

 rior dorsal margin, extending down over the sides; this much more 

 distinct than in other species. Other characters as in laticoUis. 



This species has been collected only from dead pine logs and 

 stumps. It probably does not attack hardwoods or living trees. 

 It is more common through the South. It pupates in the ground, 

 making an earthen cell, as described under imbricornis. 



Prionus sp. 



Epistoma projecting for entire width over clypeus, distended into 

 an acute tooth at distal extremities and with two larger, obtuse, me- 

 dian teeth ; front produced in a transverse bisinuate carina, divided in 

 middle; mandibles trapezoidal from outer face, more slender than in 

 other species of Prionus, not coarsely rugose, cutting edge obliquely 



