27 
Till-; ROCKY MOUNTAIN LOCUST. 
(MeUmoplus spretua I'll < 
Of all oiii- destructive locusts native to North America this in the 
one that has caused the greatest amount of damage, and consequently 
attracted to itself the general attention of the public. It is likewise 
the best known when life-history, range, habits, etc., are considered. 
As already mentioned, its distribution is so well known that it is only 
necessary to refer to this feature here. In Bulletin No. 25 of the Divis- 
ion of Entomology, a brief, but at the same time, very comprehensive 
account of this and several other locusts is given. The reader is there- 
fore referred to that publication for a more complete treatise upon the 
species now under consideration, also to the reports of the U. S. Ento- 
mological Commission for an extended account of its life-history and 
habits. 
Briefly, the Rocky Mountain Locust can be said to be a permanent 
resident of the Rocky Mountain region from northern New Mexico 
northward as far as the North Saskatchewan River, or coincident with 
the northern limits of the prairies. This range also extends out upon 
the adjoining plains, and beyond, so as to include the greater portion 
of Wyoming, a little of northwestern Nebraska, more of the western 
part of South Dakota, nearly half of North. Dakota, and much of Mani- 
toba and other parts of British America west of Lake Manitoba. Of 
course the insect is not always to be met with in destructive numbers 
over this entire region; but it is within these limits that it is always 
to be found in a healthy condition. Adjoining this " permanent v re- 
gion on the east is a strip of country of varying width of a hundred or 
more miles, that is termed the " sub-permanent " region. The insect is 
nearly as healthy and possibly equally as often to be met with here as 
in the permanent region. Beyond this secondary habitat is a still 
greater extent of country which is only occasionally visited by the 
moving swarms of the locust. This last region has on that account 
been termed the " temporary n region. . This temporary region covers 
all of the remaining portions of the States mentioned above, besides 
extending into Minnesota, Iowa, Missouri, Kansas, Arkansas, Indian 
Territory, and Texas. This region is the one that has suffered most 
during past years from the ravages of this locust. 
The description of this insect is herewith appended: 
Female. — The face nearly perpendicular, sloping under toward the breast wry 
slightly. The vertex between the eyes the same width as the frontal costa jusl 
above the ocellus: that portion in front of the eyes more or less distinctly channeled 
and deflexed at an angle of about 10 degrees from horizontal. Eyes nearly straight 
in front, about semicircular behind. Antenna' quite Blender, reaching little if any 
beyond the tip of the pronotum. Pronotum, with the sides of the anterior lobes 
parallel, the posterior lobe expanding rapidly backward ; median carina? thread- 
like, but always distinct on the posterior lobe, usualh obsolete on the anterior 
lobes; lateral carina 1 obtuse but distinct on the posterior lobe and usually 
