92 COLEOPTERA. 



resemble in form the grubs of some of the small Scara- 

 bseians. 



The shagbark or walnut tree is sometimes infested by the 

 grubs of the red-shouldered Apate, or Apate basillaris of 

 Say, an insect of this family. The grubs bore diametrically 

 through the trunks of the walnut to the very heart, and 

 undergo then transformations in the bottom of their bur- 

 rows. Several trees have fallen under my observation which 

 have been entirely killed by these insects. The beetles are 

 of a deep black color, and are punctured all over. The 

 thorax is very convex and rough before ; the wing-covers 

 are not excavated at the tip, but they slope downwards very 

 suddenly behind, as if obliquely cut off, the outer edge of 

 the cut portion is armed with three little teeth on each wing- 

 cover, and on the base or shoulders there is a large red spot. 

 This insect measures one fifth of an inch or more in length. 



The most powerful and destructive of the wood-eating 

 insects are the grubs of the long-horned or Capricorn-beetles 

 (Cerambycid^e), called borers by way of distinction. There 

 are many kinds of borers which do not belong to this tribe. 

 Some of them have already been described, and others will 

 be mentioned under the orders to which they belong. Those 

 now under consideration differ much from each other in their 

 habits. Some live altogether in the trunks of trees, others 

 in the limbs ; some devour the wood, others the pith ; some 

 are found only in shrubs, some in the stems of herbaceous 

 plants, and others are confined to roots. Certain kinds are 

 limited to plants of one species, others live indiscriminately 

 upon several plants of one natural family; but the same 

 kind of borer is not known to inhabit plants differing essen- 

 tially from each other in their natural characters. As might 

 be expected from these circumstances, the beetles produced 

 from these borers are of many different kinds. Nearly one 

 hundred species have been found in Massachusetts, and 

 probably many more remain to be discovered. 



The Capricorn-beetles agree in the following respects. 



