45 
and we find that the locusts were unusually abundant and destructive 
in the year 1885 and again in 1891. 
To give any rational explanation of this phenomenon would require 
a greater knowledge of the habits and early stages of this insect than 
we at present possess. It may be conjectured, however, that the long- 
continued and late rains retard the hatching of the young locusts, and 
at the same time produce such an abundance of vegetation that tin- 
greater number of the locusts would remain upon the breeding grounds 
the entire season and would deposit their eggs in these grounds late in 
the fall,- thus a much greater number of eggs would be deposited in the 
breeding grounds than would have been the case had the season been 
dry and the majority of the locusts migrated from the breeding grounds 
before their eggs had been deposited. The following season being a 
dry one there would not be abundance of vegetation, and the eggs in 
the breeding grounds would naturally hatch out very early in the 
spring, and the immense numbers of locusts produced would soon re- 
duce the scanty vegetation to such an extent that they would be very 
anxious to migrate to new fields as soon as they had acquired wings. 
And this would account for the immense swarms that occasionally ap- 
pear in this region, and would also account for the fact of their not 
occurring every season. 
While these locusts have been observed to migrate in swarms from 
their breeding grounds, no person has ever seen them returning to these 
grounds again, and it seems very probable that they never do so. The 
eggs of these migrating swarms are doubtless deposited in cultivated 
lands, and the subsequent plowing and harrowing of these lands evi- 
dently destroys the eggs. Thus the species must depend for its con- 
tinued existence upon the comparatively few individuals that remain 
upon the breeding grounds throughout the season, or at least until 
the egg-laying season has passed by. 
Several different persons living in the locust-infested district stated 
to me that the earlier-migrating swarms of Devastating Locusts had 
deposited their eggs in the cultivated fields and orchards, and that they 
had seen the young of these locusts in the above-mentioned places. 
Questioned closely, they all admitted that they had not seen the locusts 
in the act of depositing their eggs, nor could they refer me to a single 
person avIio had seen them thus engaged; but the fact that they had 
found what they believed were the young of these locusts in the local- 
ities mentioned, led them to believe that the earlier broods had depos- 
ited their eggs in such situations. I took especial pains to investigate 
each of these reports, but found that in not a single instance did tin' 
young locusts observed belong to the destructive migrating species. 
In the majority of cases they belong to fche young of the spineless- 
breasted locusts, but in one instance the adults of one of the short- 
winged locusts, the Pezotctti.v enigma Scudd, were mistaken tor the 
young of the Devastating Locusts; these short-winged locusts have a 
