131 
0 
LIFE-HISTORY OF LOCUSTS. 
1 
The entire life-history of but few species of the Acrididae have 
been studied, and these chiefly of the more destructive ones on ac¬ 
count of the greater interest attached to them. Although the history 
of each species has some peculiarity in reference to it which is of 
value in economic entomology, yet, in a general sense, they are so 
nearly alike that the history of one will answer for that of all. 
The female ovipositor, as we have already seen, consists of four horny 
valves, two which curve upward and two downward; with these, when 
ready to deposit her eggs, she forms a hole in the ground to a depth 
corresponding with the size of the species. The eggs are then de¬ 
posited one at a time in this hole, placed in regular older so as to 
form an elongate oval mass. During the process a glairy white fluid 
is emitted which at length hardens and binds them together and en¬ 
closes the mass giving it ultimately the form somewhat of a large 
bean. The hole above the mass is then closed with dirt intermixed 
with this fluid which, when it hardens, renders it partially at least im¬ 
pervious to moisture. The number of eggs deposited varies in the 
different species, a single mass deposited by the Rocky Mountain locust, 
(C. spretus), containing from twenty-five to thirty; the number de¬ 
posited by some other species is considerably larger, and by some prob¬ 
ably less. fh£ eggs of all the species so far observed are elongate, 
cylindrical and slightly bent or cuived; and when in the mass are 
placed in four tiers or rows, with the end in which the head will be 
formed, pointing upward, thus enabling the young insects readily to 
make their way to the surface of the ground. When the embryo is 
formed and ready to make its escape, it is enclosed, besides the outer 
shell, in a tough inner covering, which it does not wholly rid itself 
of until after it reaches the surface. 
Whether the female deposits more than one mass is yet a somewhat 
disputed point; that some species, as C. spretus , O. atlanlis and C. femur- 
rubrum, whose egg-pods contain only some twenty-five or thirty eggs, 
deposit some three or four of these pods, has been ascertained. It is 
probable that those species which deposit a much larger number in a 
mass, complete the work at one time. For example, Prof. Riley has 
counted as many ^s 171 eggs in one mass of Caloptenus differentialis; 
120 to 130 in those of Ilippiscus pJicenicopterus; and about 120 in 
those Acridium americanum. 
The particular places selected by the females for depositing their 
'eggs vary somewhat according to the species; but the form and char- 
