REHN AND HEBARD 91 



ward to Lincoln County, Nevada near Lyons, California, and in 

 California as far north as Lyons and the Inyo Mountains and as 

 far west as Cottonwood Station in the Mojave Desert and Palm 

 Springs on the western edge of the Colorado Desert. The south- 

 ward distribution of the species in Mexico is unknown. 



Biological Notes. — This species inhabits the creosote bush {Covil- 

 lea tridentata) and is found on no other vegetation. In this bush 

 in the proper situations both nymphs and adults are to be found 

 in the daytime hidden in the terminal clusters of leaflets, always in 

 few numbers and not to be secured except by vigorous and constant 

 beating, as the peculiar coloration of the insects makes them prac- 

 tically invisible in such surroundings. 



The present species although amply equipped with organs of 

 flight does not appear to fly about as much at night as does elegans; 

 this is indicated by the fact that the authors have not as yet taken 

 a single specimen of covilleae attracted to lights, which occasionally 

 bring elegans not only to camp fires but into towns at night. 



At Snyder's Hill, Pima County, Arizona, the species was found 

 more abundant than at any other locality the authors have visited 

 and ample opportunity was afforded after dark to hear its stridula- 

 tion and compare it with that of elegans. The sound produced 

 is a whirring note very similar to that of elegans but slightly 

 harsher with a ticking sound in the- whirr much more distinct. 

 These differences were so easily recognized that immediately upon 

 detecting a songster the species could at once be determined and 

 thereupon the insect, if covilleae, was invariably found in a creo- 

 sote bush and if elegans, in mesquite or other desert bush but 

 not in Covillea tridentata. ^^ 



The individuals of this species were observed to climb about the 

 creosote bush with a slow cautious movement, the males stopping 

 frequently to stridulate, both sexes, if molested, fluttering rapidly 

 from one part of the bush to another. 



Sijnomjmy. — Unfortunately the authors have confused specimens 

 of the present species with elegans three times in the past; this was 

 due to the fact that elegans was very unsatisfactorily described, few 

 specimens of it were known, and these showed sufficient variability 



=^ See note of capture of a few specimens of elegans in creosote bush in 

 biological notes for that species. 



TRANS. AM. ENT. SOC, XL. 



