400 REPORT OF NEW JERSEY STATE MUSEUM. 



Family SCOLYTID^E. 



Commonly known as "bark beetles." They are usually cylindrical, or 

 nearly so, often with the end of the elytra truncate or armed with teeth 

 in the male; the head bent down, often retracted and overshadowed by 

 the prothorax, which may be roughened or rugose, and the mouth parts 

 forming none or only a very short snout. The legs are generally short, 

 often broad and somewhat flattened, capable of being very closely folded 

 to the body. They are all borers in bark, bast or heart-wood, and almost 

 every species is as well characterized by its work as by its structure. 

 In the common type of which the "fruit bark beetle" is an example, the 

 adult beetle makes a central gallery on each side of which eggs are laid in 

 little recesses. From these eggs hatch grub-like larvae, which bore between 

 bark and wood, diverging as they increase in size. When these larvae 

 are full grown they pupate at the end of the boring, and in due time the 

 adult emerges through a little round hole. Species of this type usually 

 attack trees not quite healthy or badly injured, and when once they have 

 secured a footing in an orchard tree it might as well be cut out and 

 burned. 



Other species bore into the solid wood, and as readily into healthy as 

 sickly trees. Here the galleries are often blackened and serve for the 

 propagation of "Ambrosia," a peculiar fungus upon which both larvae and 

 adult beetles feed. Some of these forms are of extreme interest, and 

 their injury is not only direct as affecting the life of the tree, but indirect 

 as affecting the value of the wood for timber. 



The classification of the family is in an unsatisfactory condition at 

 present. There are many undescribed species and many that are undeter- 

 mined in collections. Dr. A. D. Hopkins, of the U. S. Department of Agri- 

 culture, has been studying the group for some years, but has not yet pub- 

 lished the results of his labors except in "Dendroctonus." The present 

 list, therefore, merely adds a few species, some new localities and a little 

 additional information concerning food habits. 



PLATYPUS Hbst. 

 P. flavicornis Fab. Sea Isle VII, 4 (Brn); Anglesea V, 21 (div). 



CORTHYLUS Er. 



C. punctatissimus Zimm. Eagle Rock (Bf) ; Staten Island (Lg); Cape 

 May C. H. X, 22, cut out of roots of huckleberry, readily noted by 

 yellow dust on surface of ground (W) ; boring in green sassafras 

 (Hpk). 



C. columbianus Hopk. 5-mile beach, cut out of toad stomachs VII, 4; 

 bores into healthy oak and other hardwood trees (W). 



