356 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
bauds that the beetle Lfl 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 u protective mimicry," being protected from the 
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 month of September these beetles gather on the locust trees, where they may 
beseen glitteriug in the sunbeams with their gorgeous livery of black velvet and gold, 
coursing up ami 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 antenna-, and dropping therein her snow-white 
in clusters of seven or eight together, and at intervals of five or six minutes, till h^r 
whole stock is safely stored. The eggs are soon hatched, and the grubs immediately 
burrow into the bark, devouring the soft inner substance 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 aud irregular passages beiug in an upward direction 
from the place of their entrance. For a time they cast their chips out of their holes 
M fast as they are made, but after a while the passage becomes clogged and the bur- 
row more or less tilled with the coarse and 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 ooziug 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 suffered. 
According to the observations of General H. A. S. Dearborn, who has given an ex- 
cellent account of this iusect, the grubs attain their full size by the 20th of July, 
soon become pupa?, 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. jrictus iu the hickory, states (Proc. Ent. Soc. 
Phil., i, 30) that its excavations are immediately subcortical. "Unlike the Clytns 
erythrocephalus, 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 aud 
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 iuthe direction of its previous subcortical dwelling, it under- 
goes its transformation, and requires about two aud sometimes three weeks for 
becoming a perfect iusect." 
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 Juue, according to 
Walsh, who has claimed that the males of the hickory brood differ 
from those of the locust brood iu having ;k much longer and stouter 
legs and much longer and stouter autennae, aud in having [their bodies] 
tapering behind to a blunt point"; on the other hand the females are 
not distinguishable, nor the larva?. On this account Mr. Walsh re- 
garded the locust and hickory broods as representing two distinct 
