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 n 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 Calopltmus minor 

 were noticed among the dense vegetation along boggy and damp places. 

 After coming out of the park and enteriug 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). Stenobothras occipitalis, 

 a species with light gray antennae, 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 ; aud, 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 W3 T oming, 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 ?, 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 (Edipodinw 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, aud during such times are very 

 active and remarkably noisy, being almost incessantly in the air, where 



