, 
58 BULLETIN NO. 4, DIVISION OF ENTOMOLOGY. 
semblance of the noise made by the males to the rattling of a rattle- 
snake. 
At Laramie River, where some little time was occupied in collecting, 
we obtained, in addition to such forms as were taken in the vicinity of 
Fort Collins, a few specimens of a greenish-white Psoloessa that was only 
observed to feed upon the “ sweet” or mountain sage. In the North Park 
no additional species were taken or noticed, while all forms appeared 
to be rather scarce and wild. The genus Arphia, however, seemed to 
be the best represented in forms. A few specimens of Caloptenus minor 
were noticed among the dense vegetation along boggy and damp places. 
After coming out of the park and entering the Laramie Plains on the 
west side of Laramie River, a few locusts, though nothing new, were 
taken. On the 18th of July a few specimens of a light greenish Gom- 
phocerus were taken at Aurora, where they were found to be partial to 
the common sage-brush (Artemisia tridentata). Stenobothrus occipitalis, 
a Species with light gray antenne, was also taken. 
Between Rock Creek and Fort McKinney but very few locusts of any 
kind were noticed, and none were taken. At Fort McKinney we 
captured a large number of various species of locusts, among which 
were several of interest, on account of their rarity in collections as well 
as in their peculiar habits. During the summer we observed that quite 
a number of locusts are partial to certain food-plants; and, as a rule, in 
all such cases they imitate in color, to a certain degree, very closely the 
plant or plants upon which they feed. 
Pezotettix albus, Dodge, feeds upon a white Artemisia. Pezotettix 
borckii, which is only to be met with in the mountains of Montana. Idaho, 
and Wyoming, appears to abound only where two or three particular 
plants are met with, one of which is a species of geranium. Again, 
Caloptenus turnbullii, which is found in the vicinity of Custer’s battle- 
field, only feeds upon two species of plants, as nearly as I could ascer- 
tain by observation, viz., the “ pig-weed” and a small greenish-white 
plant of a similar nature. Those found on the pig-weed are somewhat 
glaucous yellow, while those feeding on the other plant are more of a 
whitish color. mingled with greenish blue instead of greenish yellow. In 
like manner two species of Caloptenus, perhaps the Melanoplus devastator 
and the M. cinereus of Scudder, feed upon the sage brush (Artemisia 
borealis 2, ard A. tridentata). The latter is grayish in color, and when at 
rest, both in the preparatory and the imago stages, is difficult to detect, 
so nearly does its color coincide with that of the plant upon which it is 
resting. Other locusts are not partial to certain food-plants, but appear 
to be so to certain soils and surroundings. For example, all those species 
of Gdipodine which would naturally fall under Mr. Scudder’s genus Cir- 
cotettix, love barren and rocky slopes and hillsides, the different species 
living at different altitudes and on differently colored soils. The spe- . 
cies all love bright and warm sunshine, and during such times are very 
active and remarkably noisy, being almost incessantly in the air, where 
