139 



riihrum fiatcli iiuj.stly in Miiy, the youjig feeding and growing during 



June and .July and maturing in about seventy days. Scattering adults 



may ai>i)ear in late June and in July, but the bulk of the species 



mature early in August. Differcntialis has a similar history. Bivittatus 



and atlanif<, on the 



other hand, appear as 



adults early in July, 



and disappear at a 



corres|K)ndingly early 



peri(Kl in fall. All 



these grasshopj>ers are 



singl(!-})rooded as a 



rule, but atUxnis and 



spretus may be two- 



broodecl southward. 



The Rocky Moun- 

 tain species, as every 

 one knows, is very de- 

 structive during its 

 great migrations to the 

 east. Atlanis is also 



migratory and destructive now and then in some eastern localities. The 

 three smaller species prefer open country and short grass. The two larger 

 ones are more common in moist rank grass along fences, ainong tall weeds, 

 and near streams. The permanent home; of the Rocky Mountain grass- 

 hopper is in the mountain country, from which it migrates at irregular 

 intervals; that of allania is on dry slopes and lesser hills and mountains; 

 while femur-ruhrum, which is not common in the Atlantic region, prefers 

 the low, lev(!l lands of the Mississippi valley. The two last mentioned 

 occur in nearly all parts of the United States, except that femur-ruhrum 

 is replaced by another species in Florida and its neighborhood. Differ- 

 cntialis is especially central and western in its range but has been taken in 

 New Jersey. Bivittatus proper, the form with ycillow tibijc, is principally 

 western; but femoratus, with red tibiae, is mostly eastern, and is the 

 common form in Illinois. 



Flfj. 126. The Rocky Mountain Grasshopper, M clunoplus apre- 

 tus: a, a, a, fenriales ovipositing; b, estg-pod removefi from ground, 

 with end broken open showing eacgs; c, eggs; d, e, egg masses in 

 tlie ground; /, egg mass completed and covered up. Natural 

 size. 



"■J'hk (Jlp:ar-winged Grasshoppkh. 



C/imnula <pellucida Scudd. 



'i'liis is the most d(;structive grasshopper of northern North America, 

 and barely reaches at times within the northern boundaries of Indiana 

 and Illinois. It has the migratory habit, but its migrations are not 

 definitely directed like those of the Rocky Mountain grasshopper. It 

 is often excessively abundant, and frequently destroys considerable 



