221 
full and interesting, and is appended. The variation in life history 
referred to above consists in the fact that the insect hibernates as an 
adult, and lays its eggs in May and June. Most other injurious spe- 
cies, it will be remembered, lay their eggs in the autumn, and these 
eggs hibernate. Late fall and winter plowing, therefore, usually affords 
a good remedy in the case of other species. With the American locust 
other means have to be adopted, and these are found in the use of 
hopper-dozers while the insects are yet unfledged, and in the use of the 
bran-arsenic mash for both unfledged and winged individuals. Experi- 
ments tried by Mr. Coquillett, and which are detailed in his report, 
show that the poisoned mash seems very attractive to this species, and 
indicate that by its use at the proper time much damage may be pre- 
dented. 
The cause of this extraordinary local abundance of the insect is diffi- 
cult to ascertain. Mr. Coquillett is inclined to follow the popular local 
opiuion in attributing it to a successful hibernation on account of the 
mildness of the winter of 1893-'94. As a general rule, however, we 
Fig. 20.— Schistocerca arnericana : a, first stage; b. second stage; c, third stage — enlarged twice 
(original). 
believe that mild winters, particularly when followed by late and severe 
spring frosts, as was the casein the spring of 1894, are not so favorable 
to successful hibernation as uniformly severe winters, and we are 
inclined to think that we must look further for the cause of this out- 
break. Last year extensive forest fires in the region about Roanoke 
may have had some influence. The comparative drought of the present 
summer may have been favorable to the development of the insect in 
greater numbers than usual. Other and unknown causes, appearing 
to produce a smaller number of natural enemies than customary, may 
also have been immediate factors. Such speculations, however, are of 
little practical account, and the important fact is that the insect was 
present in great numbers and may increase and spread another year. 
Curiously enough, although the species is everywhere common 
throughout the South, its early stages have not been figured, and. so 
