BARK-BEETLES; ENGRAVER-BEETLES. 



233 



Toiiiiciis. Dcndroctoniis, Hylastes, and others; and such beetles 

 have to be constantly fought in well regulated pine forests to pre- 

 vent heavy losses. Dendroctonus frontalis is illustrated (Fig. 

 246), to show the form of such beetles ; and a still larger one, very 

 common in our pine forests, the D. terebrans Oliv., in Fig. 247. 



There is still another beetle belonging to this family that 

 -deserves at least passing notice, as it may find its way to our 



Fig. 247. — Dendroctonus terebrans, 

 Oliv. After Division of Ento- 

 mology, U. S. Department of Agri- 

 culture. 



Fig. 248. — Hylesinus trifolii, IMuell. 

 After Division of Entomology, V . S. 

 Department of Agriculture, 



state in the future. It has the rather abnormal habit of making 

 burrows in the roots of clover and allied plants, and it has be- 

 come a very serious pest in the Eastern States into which it 

 found its way from Europe. A large proportion of the two 

 year old clover plants are destroyed by this insect which can be 

 found in all stages in such snug quarters during the winter 

 months. The clover-root Borer (Hylesinus trifolii ]\luell.), is il- 

 lustrated in Fig. 248. 



