26 
Also in years when they hatch and prevail in the temporary region 
their migration therefrom in early summer is virtually complete and no 
disastrous incoming swarms visit the same region later in the season. 
Single-broodedness is then the rule. Where the species has been ob- 
served to breed for 2 or 3 consecutive years, as in Minnesota and north- 
erly regions, only one annual generation is produced. Those swarms 
which reach Manitoba from the south in early summer lay eggs the 
bulk of which remain nnhatched till the following spring. The same 
was observed in Minnesota in 1873, the eggs laid that year remaining 
mostly unhatched until 1874. This rule may have exceptions. Many 
insects are single-brooded at the northerly limit of their range, but 
double-brooded farther south, and the premature hatching of the eggs 
of this locust in autumn in southerly regions is a step in this direction. 
But it has been conclusively shown that it can not establish itself under 
more southern climatic influences which suit some of its related species, 
but can breed permanently only under those conditions which induce 
single-broodedness. 
Hibernation. — From the facts just stated it will be seen that the nor- 
mal hibernation is passed in the egg state. Though many Acridiidae 
hibernate in the imago or even the pupa state, under bark, logs, or 
stones, the species under consideration after laying its eggs in the 
summer lasts until autumn, but dies with the approach of cold weather. 
THE LESSER MIGRATORY LOCUST. 
(Caloptenus atlanis Riley.) 
Range of Species. — G. atlanis, in common with the next species, G. 
femur-ruhrum, has a very extended natural range, breeding annually in 
abundance from middle Florida nearly to the Arctic circle, in many 
places entirely replacing the latter species. It becomes less common 
■v*.** 
Pig. 4. — Caloptenus creams, anal characters of male; a, from above; b, from aide; c, from above, 
enlarged six times (after liiley). 
towards the Mississippi, G. femur -rubrum generally predominating, 
while it gives way to spretus on the great plains. It, however, rather 
strangely, considering that it is essentially an eastern species, again ap- 
pears toward the Pacific in the more northern regions extending from 
about the fortieth parallel in Utah and California as far north as the 
Yukon River. 
