HABITS OF LOCUSTS. 191 



plague," of which the youngsters are thought to be the advance 

 guard. These hibernating young are the first to reach maturity 

 the next spring, in Indiana usually becoming full grown about 

 the 20th of April. 



In the latitude of central Indiana the heyday of the mature 

 locust's life lies between the dates of mid-August and mid-Octo- 

 ber. Then it is that their love calls are most numerous, that their 

 ambitious in life are satisfied, and that the eggs, destined to carry 

 the race through the rigors of an approaching winter, are depos- 

 ited in the earth. As the cooler days of November draw nigh their 

 ranks grow raj idly less, and yet, with the exception of one place, 

 their dead bodies are seldom met with. That exception is the 

 tops of tall weeds where, oftentimes even so early as September, 

 the bodies of the more common species are seen (Fig. 15), their 

 limbs tightly grasping the branches or leaves of the plant on 

 which they rest. Why this position is taken by them before death 

 I cannot say. Of course it is nonsense, but I have often asked my- 

 self the question : "Is it assuming too much of them to suppose 

 that, having lived their allotted time, or being preyed upon by 

 some invisible but insidious animal or plant parasite, and feeling 

 their death throes coming on, they choose to fly or climb to the 

 most elevated position available, there to take a farewell view of 

 their summer's home?" 



A number of species of Acrididse, especially of those belonging 

 to the genus Melanoplus, possess, in the adult stage, only rudi- 

 mentary tegmina and wings, and resemble immature insects or 

 nymphs in appearance. A close examination will show, however, 

 that these adults have the tegmina in the proper position, while 

 in the immature stages of these and other forms, the tegmina and 

 wings are inverted, being twisted about so that the faces and 

 margins are just the opposite to what they are in the perfect 

 insect. 



About 140 species of the family Acridida? are known from the 

 eastern United States. These are divided among three subfamilies, 

 each of which is represented in our eastern fauna by numerous 

 species. 



KEY TO THE SUBFAMILIES OF ACRIDIDvE. 



a. Prosternum without a spine or tubercle between the front pair of legs- 



b. Pace more or less oblique, usually meeting the vertex at an acute 



angle; foveolse usually absent or invisible from above; median 



carinfe of pronotum never raised in the form of a crest or cut 



by more than one sulcus; wings nearly uniformly transparent, 



