192 TRANSACTIONS OF THK ILLINOIS 



Dicer ca divaricata, Say. The Cherry-tree Borer. 



This species is of a bright coppery or bronze color throughout, varied 

 only by a few small, oblong, raised, black points on the wing-cases; the 

 head and thorax are somewhat roughened or granulated ; the wing-cases 

 are elongated, tapering much behind, this portion being elongated, 

 suddenly cut off at the tips, where the two cases are separated or 

 parted from each other. The length varies from seven to nine tenths 

 of an inch; the width is rather less than half the length. 



The larvae, so far as I am aware, have not been described, nor have 

 I had any opportunity of examining them; but we may reasonably 

 presume they are similar in form to those of Chrysobothris femorata. 

 Their attacks appear to be directed chiefly against the wild and cultivated 

 cherry trees; they are also found occasionally boring into the peach tree, 

 and Dr. Le Conte adds the beech. 



The perfect insects are to be found, from June to August, basking in 

 the sunshine on the limbs of these trees. It is found in Illinois but 

 rather sparingly, as I have not taken a single specimen in the southern 

 part of the State. 



Spec. Char. Imago. — Of a shining bronze or copper color throughout, rather deeper 

 beneath than above; head and thorax coarsely punctured, so as to give them a gran- 

 ulated appearance; the thorax is slightly furrowed in the middle, and has the posterior 

 lateral angles acute. Elytra striate; marked vi^ith some oblong, raised, black dots, 

 arranged somewhat in lines parallel with the striae; elongate, acuminate posteriorly, the 

 extreme points truncate and separating fronj each other. The breast is furrowed ; the 

 males are furnished with a little tooth on the under side of the middle tibire. 



Length varies from seven-tenths to nine-tenths of an inch ; the width about three- 

 tenths of the length. 



Dicerca lurida, Fabr. 



This species so closely resembles D. divaricata that it is difficult to 

 distinguish one from the other. This is rather darker than the former 

 and of a less brilliant metallic lustre ; the black points on the elytra more 

 numerous ; the tapering portion of the wing-cases not so elongated, and 

 the tips, which are blunter, are each furnished with two little spines, 

 which point backward. The length is rather more than half an inch. 



The larvae of this species appear to confine their operations to the 

 hickory, in which they burrow ; but, as a general rule, I think such trees 

 only are infested by them as are already in a state of decay. 



Spec. Char. Imago. — Very similar to the preceding species, but is rather darker 

 above, being a dull, dark, brassy color ; the black dots on the elytra are more numerous; 

 the thorax is not so coarsely punctured and is smoother, yet apparently very finely gran- 

 ulated. The elytra are not so distinctly striated ; acuminate posteriorly, but not quite 

 so elongated as in divaricata : the tips rather blunter, and each furnished with two 

 sharp little spines, which point backward, separating slightly at the tips. 



Length varies from a little less than five-eighths to three-fourths of an inch; width 

 one-third the length. 



I am not aware that either of these species of Dicerca have proved 

 injurious to any considerable extent in this State ; if they should become 

 troublesome, I presume the remedies used against 'the flat-headed borer 

 {Chrysobothris femorata') would be equally effectual against them. 



