356 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



bands that the beetle is nearly all of the shade of deep golden yellow^ 

 peculiar to the flowers of the golden rod, and thus the insect is an 

 interesting case of " i^rotective mimicry," being protected from th& 

 attacks of birds, etc., by their liability to be confounded with the yel- 

 low heads of the golden rod. 



The best account of these insects has been given, as follows, by 

 Harris : 



In the mouth of September these beetles gather oa the locust trees, where they may 

 be seen glittering iu the sunbeams with their gorgeous livery of black velvet and gold, 

 coursing up and down the trunks in pursuit of their mates, or to drive away their 

 rivals, and stopping every now and then to salute those they meet with a rapid bow- 

 ing of the shoulders, accompanied by a creaking sound, indicative of recognition or 

 defiance. Having paired, the female, attended by her partner, creeps over the bark, 

 searching the crevices with her antenn;B, and dropping therein her snow-white eggs, 

 in clusters of seven or eight together, and at intervals of five or six minutes, till her 

 whole stock is safely stored. The eggs are soon hatched, and the grubs immediately 

 burrow into the bark, devouring the soft inner 8u})stance that suffices for their nourish- 

 ment till the approach of winter, during which they remain at rest in a torpid state. 

 In the spring they bore through the sap-wood more or less deeply into the trunk, the 

 general course of their winding and irregular passages being in an upward direction 

 from the place of their entrance. For a time they cast their chips out of their holes 

 as fast as they are made, but after a while the passage becomes clogged and the bur- 

 row more or less filled with the coarse aud fibrous fragments of wood, to get rid of 

 which the grubs are often obliged to open new holes through the bark. The seat of 

 their operations is known by the oozing of the sap and the dropping of the sawdust 

 from the holes. The bark around the part attacked begins to swell, and in a few 

 years the trunk and limbs will become disfigured and weakened by large porous 

 tumors, caused by the efforts of the trees to repair the injuries they have suflfered. 

 According to the observations of General H. A. S. Dearborn, who has given an ex- 

 cellent account of this insect, the grubs attain their full size by the 20th of July, 

 soon become pupse, and are changed to beetles and leave the trees early in Septem- 

 ber. Thus the existence of this species is limited to one year. 



Dr. Horn, who has observed C. pictiis in the hickory, states (Proc. Ent. Soc. 

 Phil., i, 30) that its excavations are immediately subcortical. "Unlike the Clytus 

 eryihrocephalus, which also bores in the hickory, its course is not in a line, but it 

 bores in every direction, making extensive excavations. Its borings are coarse and 

 sawdust-like, and are packed with considerable firmness. When about to become 

 pupa the larva bores for a slight depth into the wood, and for a distance of about 3 

 inches. The aperture is closed with some very coarse splinter-like borings, and after 

 having turned its head in the direction of its previous subcortical dwelling, it under- 

 goes its transformation, and requires about two and sometimes three weeks for 

 becoming a perfect insect." 



As is well known, Cyllene pictus attacks the walnut and hickory, 

 and occasionally the honey locust, but those individuals living in these 

 trees, unlike the locust brood, evolve the beetle iu June, according to 

 Walsh, who has claimed that the males of the hickory brood differ 

 from those of the locust brood in having " much longer and stouter 

 legs and much longer and stouter antenuiie, and in having [their bodlesj 

 tapering behind to a blunt point"; on the other hand the females are 

 not distinguishable, nor the larvte. On this account Mr. Walsh re- 

 garded the locust and hickory broods as representing two distinct 



