151 



Clytus (Glycobius) speciosus. — Say. (The Sugar-maple Borer.) 



The various species of this genus (Clytus) are distinguished by 

 their convex or rounded form, and by the nearly globular or barrei- 

 sharjed thorax, which is neither flattened nor indented, and mostly 

 smooth. Quite a number of species are found in Illinois, all boring 

 in the larva state, into trees or woody plants and hence more or less 

 injurious. This and the following species are briefly described as 

 examples. 



It is found in the northern part of the state, but as yet I have cap- 

 tured none in this section. The body is black; head with yellow 

 band on the front above the antennae j antennae black ; thorax globu- 

 lar, with two oblique yellow spots each side, the latter being the 

 longest. The wing-cases, when closed, appear thus.: A yellow spot 

 on each shoulder, a diagonal line on each running outward from the 

 scutel ; next, a zigzag line running across both, forming a W ; next, 

 a narroAv transverse band, then another a little wider, and finally, the 

 tips have a broad band of the same color (yellow), with a spot each 

 side of the suture of black. The intermediate color between these 

 bands is a purplish-black ; length about one inch; width one-third. 

 The larva bores into the sugar maple. 



Clytus (Cyllene) robintje. — Forst. (The Locust-tree Borer.) 



Antennse brown, shorter than the body, inserted in a notch in the up- 

 per side of the eye; a yellow cross band on the head immediately behind 

 the antennae; another band along the hind margin of the head, which 

 borders the eyes behind, curving around and then on the cheek; 

 thorax barrel-shaped, black, encircled by four yellow bands ; wing- 

 cases brown, crossed by five zigzag, whitish lines, shoulders and tips 

 margined with the same ; breast and abdomen striped with yellowish- 

 white bands; length five-eighths of an inch, width one-sixth. The 

 perfect insect appears in the latter part of summer and commence- 

 ment of fall. The larvae which are hatched out in the fall depredate 

 upon the locust (R. pseudacacia), eating the sap-wood and perforating 

 the trunk. I have before me now a grub taken from a locust standing 

 in the street. It is scarcely half grown, as they do not finish their 

 larval state until the next season after hatching out. It is a rather 

 slender grub, with a reddish-brown head, having a triangular de- 

 pression in front and a central scollop behind, the skin of the segment 

 rolling loosely over the posterior margins. It is of a pale yellow color, 

 with six very minute feet. 



Clytus (neoclytus) capr.e. — Say. (The Ash-tree Borer.) 



Dark brownish purple, head and thorax darkest ; eyes nearly cir- 

 cular, behind them a narrow yellow border ; thorax barrel-shaped, 

 deep purple, surrounded by three very narrow yellow lines, one at 

 each end and one in the middle; scutel yellow ; wing-cases crossed by 

 three yellow bands : first, a semi-circular band from the scutel running 

 backwards and round up to each shoulder ; then another of similar 

 shape about the middle, with the circle reversed; then a straight band, 

 and a strong spine at the tip of each; length half an inch; width 

 one-seventh of an inch. This is quite common in southern Illinois. 



The larva of this species bores in the ash. 



