284 
AMERICAN AGRICULTURIST. 
[ J ULY, 
in the fourth stage, or after the third moult. 
After the fourth moult we have the true pupa 
stage (fig. 3, e), and with the fifth moult the wings 
are acquired, the process being illustrated at figure 
4. The time required from hatching to full de¬ 
velopment varies according to season and weather, 
cold and wet weather retarding, and warm weather 
accelerating development. It averages, however, 
Fig. 3.— a, a, newly hatched larvae; b, full-grown larva , 
c, pupa of the locust. 
two months. There is but one generation each 
year, the term of the insect’s life being bounded by 
the spring and autumn frosts. 
Food Plants. —The Rocky Mountain Locust, 
when hard pushed will feed upon dry bark of trees, 
or dry lint of timber; upon paper, cotton, and wool¬ 
len fabrics, as well as upon the more helpless of its 
own kind. It has even been known to feed upon 
dead animals. Yet, when proper food is plenty, it 
prefers acid, bitter, or peppery plants to sweet ones. 
Destructive Powers. —The destructive powers 
of these insects have been dwelt upon from the 
earliest times. I cannot better illustrate their 
work than by quoting the following from the First 
Report of the U. S. Entomological Commission: 
“ Falling upon a cornfield, the insects convert in 
a few hours the green and promising acres into a 
Fig. ■!.—Process of acquiring wiugs ; a, pupa with skin just split on the back; b, the imago extrud¬ 
ing ; c, the imago nearly out; d, the imago with wings expanded ; e, the imago with all parts perfect. 
desolate stretch of bare, spindling stalks and stubs. 
Covering each hill by hundreds ; scrambling from 
row to row like a lot of young famished pigs let 
out to their trough ; insignificant individually, but 
mighty collectively, they sweep clean a field 
quicker than would a whole herd of hungry steers. 
Imagine hundreds of square miles covered with 
such a ravenous horde, and one can get some real¬ 
ization of the picture presented in many parts of 
the country west of the Mississippi during years of 
locust invasion.’'’ 
Migration, Flight.— The winged insects make 
extensive flights, the movement of migrating hordes 
being steady and long-sustained. The insects 
often rise to a hight at which they are lost to 
human vision,and they have been seen with the tele¬ 
scope as far above the highest peaks of the Rocky 
Mountains as the instrument would resolve them. 
The rapidity of flight depends almost entirely upon 
the velocity of the wind, which they know well 
how to make use of. They rise as by a common 
instinct when the sun has dissipated the dew, and 
generally descend again toward evening; but under 
favorable circumstances they can and do continue 
their flight during the night and may travel 400 or 
500 miles at a stretch. It is by means of these ex¬ 
tended flights that they swoop down upon the 
fertile States of the Mississippi Yalley, carrying 
destruction in their wake. 
The Locust dwells habitually in the plains and 
plateaus of the Rocky Mountain region north of 
Pike’s Peak, but particularly in the vast plains east 
of tue Mountains on either side of the boundary 
line between the United States and British America, 
and extending toward the north. Whenever the 
conditions are favorable to their excessive multi¬ 
plication there, viz., after two or three years of un¬ 
usual drouth, they migrate in immense swarms and 
extend over most of the country west of the Mis¬ 
sissippi, never reaching east, however, much beyond 
the meridian of St. Paul, and never quite reaching 
the Gulf, but stopping within40 or 50 miles of Gal¬ 
veston. We have the invading swarms from the 
native habitat one year, and the return swarms 
thereto the following year, the former occurring 
in late summer and fall, and aided by the pre¬ 
vailing winds which, at that season are from the 
northwest, the latter occur¬ 
ring in early summer, and 
similarly aided by the pre¬ 
vailing winds which, then, 
in the Mississippi Valley, are 
from the south or southeast. 
Enemies. —The Locust has 
a large number of enemies, 
almost all birds that occur in 
the western country feeding 
readily upon it, and many 
reptiles and quadrupeds do¬ 
ing likewise. An interest¬ 
ing and effective enemy is 
the Locust Mite (Trombidium 
locustarum), living as a six-legged larva attached to 
the wings and the body of the mature locust, and 
feeding in the perfect state upon the eggs. The 
larvse of our common Blister-beetles, and those of 
the Bee-flies ( Bombyliidcc ), are frequently found 
destroying the eggs of the destructive locust. 
Remedies. —The farmer has been, so far, com¬ 
paratively at the mercy of the winged swarms that 
come unbidden, 
and frequently 
unheralded, but 
he can effectually 
battle with the 
unfledged insects 
as they hatch out 
upon his farm or 
threaten toinvade 
it from neighbor¬ 
ing fields. Har¬ 
rowing over the 
ground infested 
with eggs or any 
mode of disturb¬ 
ing these and ex¬ 
posing them will 
prove useful, but, 
as a rule, all efforts to diminish the number of eggs 
will prove more or less unsatisfactory. The fight is, 
therefore, with the young insects. Their habit of 
huddling together under shelter during cool nights, 
for some time after they are hatched, permits 
them to be trapped in windrows of straw or hay, 
and then burned in myriads. Judicious ditching 
will protect a field from invasion, and there are 
hosts of devices for 
bagging and crushing 
them. The most sat¬ 
isfactory, and cheap¬ 
est way of destroying 
them is by the use of 
kerosene, and a simple 
sheet-iron pan made 
after the plan shown at 
figure 5, or something 
still simpler, as shown 
at figure 6. The bot¬ 
tom of the pan is thin¬ 
ly covered with coal 
oil or tar, and drawn 
by lads, or, if made 
very long and heavy, 
by horses. The young ’hoppers jump into the pans, 
and, no matter whether they jump out again or not, 
the slightest touch of the coal oil is sure to prove 
fatal. The greatest number perish within the 
pans, which have to be emptied occasionally ; the 
dead locusts thus collected should be buried. 
Another way of using coal-oil in those parts of 
the West where irrigation is resorted to in agricul¬ 
tural operations, is to float a little of the oil upon 
the water in the ditches. A simple mode of doing 
this is by perforating a tin can on the sides near the 
bottom, a chip of wood to be loosely inserted in 
the aperture. The can is then tilled with tar or oil, 
and sunk (by a weight if necessary) in the ditch. 
Three quarts of tar or oil, trickling out drop by 
drop through this orifice, will keep the surface of 
the ditch supplied with a faint scum for nearly two 
days, and all locusts driven in such a ditch are de¬ 
stroyed. Fruit trees, and other valuable trees, are 
often seriously injured by these locusts, especially 
when they have acquired the pupa state. Simple 
whitewashing will largely protect them, as the lime 
5.— LARGE COAL-OIL PAN FOR CATCHING THE LOCUSTS. 
crumbles under the feet of the insects as they at¬ 
tempt to climb. Still, it has to be repeated, and 
there is no better or cheaper protection in the long 
run than a strip of bright tin, from 4 to 6 inches 
wide, brought around and tacked to the tree. If 
the tree is very rough, the tin should be tacked to 
a piece of old rope, or other material, that will fill 
up depressions, and prevent ascent underneath. 
The tin should be high enough from the ground to 
prevent the insect from jumping from the latter be¬ 
yond it, and a little coal tar, or some poison should 
be used below the tin to prevent girdling. 
In thickly settled communities it is quite possi¬ 
ble, by concentrating the efforts of the whole peo¬ 
ple, in the manner described, to either drive off or 
destroy the bulk of such swarms, as the Mennonites 
so often do. Diversified agriculture is one of the 
best safeguards against locust injury. There are 
many plants that are more or less distasteful to the 
locust, and are left untouched unless the swarms 
are very heavy and have devoured everything else. 
Such plants are peas, castor beans, sorghum, 
broom corn, tomatoes and sweet potatoes. 
Prospects.—T he western farmer is always great¬ 
ly concerned as to the prospects. There are cer¬ 
tain laws governing this insect, which enable us to 
predicate as to its future with tolerable accuracy 
within certain definite periods. I am warranted, 
from last year’s observations, in expressing the be¬ 
lief that we shall have no serious trouble the pres¬ 
ent year. A few light swarms were noticed last au¬ 
tumn, and in some restricted parts of Texas they 
alighted and laid eggs. In parts of Colorado they 
have also hatched out in limited numbers the pres¬ 
Fig. 6.—A SIMPLER FORM OF A COAL-TAR PAN. 
ent spring, and we may expect local injury, but no 
wide-spread flights or destruction. A study of the 
records of past general injury shows that such years 
recur on an average of about eleven years, and 
should the present year, and 1882 and 1883 prove 
extremely dry in the Northwest, I have little doubt 
that about the middle of this decade our western 
farmers will again suffer materially from the locust. 
