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NOTES
ON THE
L O C TT S T A
SEPTENTRIONALIS AMERICANS DECEM SEPTIWA.
BY NATHANIEL POTTER, M,D,
PROFESSOR OP THE THEORY AND PRACTICE OF MEDICINE^ IN THE UNIVERSITY
OP MARYLAND, &C, &,C.
" Still the green soil with joyful, living things
Swarms : the wide air is full of joyous ^nngs,
And myriads still are happy in their sleep."
BBTANT
BALTIMORE:
PRINTED BY J. ROBINSON
1839.
NOTES
ON THE
LOCUSTA
SEPTENTRIONALIS AMERICANS DECEM SEPTIMA.
BY NATHANIEL POTTER, M,D,
PROFESSOR OF THE THEORY AND PRACTICE OF MEDICINE, IN THE UNIVERSITY
OF MARYLAND, &C. &C.
" Still the green soil with joyful, living 1 thing's
Swarms : the wide air is full of joyoustfing-a,
And myriads still are happy in their sleep."
BRYANT.
BALTIMORE:
PRINTED BY J. ROBINSON.
|
1839.
BIOLOGY LIBRARY
BIOLOGY
LIBRARY
EXPLANATION OF THE PLATE.
Figure}. Female of the natural size, b, The ovipositor.
Fig. 2. Male of the natural size, a, a, Scales covering the membranes
of the large cavities
Fig. 3. Side view of the natural size.
fig. 4.
Fig. 5.
with the excavations made by the female (a, a, a, a, , a,) ; 6, a
part of the wood cut away so show the situation of the eggs.
fig. 6. An egg magnified 1000 times.
Fig. 7. A young insect just from the egg, magnified 1000 times.
fig. 8. Ovipositor, magnified 10 times, to show the saw teeth of the
edges, (a,) and rasps of the blade.
Fig. 9. Parts of the ovipositor separated and magnified, showing the
form of the saws and rasps, (a,) and of the oviduct, b.
Fig. 10. The Rostrum or Snout magnified, to show the capillaries, (a,)
slightly protruded.
Fig. 11. A section of the chest of the male at the upper ring, showing
the internal structure, and the external musical membranes, or
drums, a, a, The posterior walls of the large cavities within the
chest, being white silky membranes. 6, b, The external musical
membranes or drums, c, Two bundles of muscular fibres, con-
nected together at the top, and to the sides of the chest at the
bottom of each, d, The cavity of the chest, spanned by the two
bundles of muscular fibres.
ERRATA.
Page 1 . For Mosse, read Moses.
" 12. For of fasciculi, read of the fascicule.
" 17. For hybirnating, read hybcrnating.
" 22. For Thycides, read Thyoides.
" 24. For grass, read gross.
M85B04
NOTES, &c.'
THE title of the following disquisition admonishes the reader,
that he is not to expect a perfect analysis of a subject environed
by so many difficulties, and that we cannot avoid some obscurity,
and much repetition. The irregularity and promiscuous character
of our notes, observations and experiments, will render it still more
difficult to observe a lucid order.
As we are not the first who have essayed this difficult problem,
a due respect for our predecessors requires us to notice their im-
pressions.
The first account we have found, is from the state of Massachu-
setts, where every thing remarkable or interesting has been recorded
for the benefit of the past, present and time to come. It is to be
found in a work entitled New England's Memorial, written by
Nathaniel Moreton, in 1669. He witnessed an ascension of the
locust in 1663. He says very little of its character, but mentions
an ancient tradition of the native Indians, which associated the
ascension with the appearance of pestilential diseases. Both reason
and experience shew that there can be no natural connexion be-
tween two occurrences, that must either be the offspring of imagi-
nation or accidental coincidence.
The next in chronological order is to be found in a memorandum,
left by the Reverend Andrew Sandel, Rector of the Sweedish Con-
gregation, at Philadelphia, dated 1715. He scarcely alludes to
the character of the insect, but states a fact known to all countries
where the larger varieties of the cicadas or locusts are known
that the natives use them as an article of diet. Doctor Pocock,
and other travellers through .ZEgypt, mention the Gryllus Migra-
torius as a common article of consumption.
In Dosley's Annual Register for 1767, we have a more particu-
lar account by that excellent naturalist, Mosa Bartram, of Penn-
i?, in a letter addressed to Peter Collinson, Esq. of London.
H^ gave a cc<i account of the rise and progress, both as to habits
and appearance, and only wanted the use of the microscope to
have accomplished MUCH more.
In the 10th volume of Silliman's Journal of Science and Arts,
we have a contribution by Doctor S. P. Hildreth, of Marietta,
dated 1829. It contains many useful facts and reflections, that
have been corroborated by our observations and experiments; and
if he had called to his aid the power of good glasses, he would
have been led to important results.
In 1834, the date of the most material of our observations,
James R. Williams, of this city, instituted an inquiry, and if he
had been permitted to devote time enough to the pursuit, would
have far surpassed his predecessors, as he availed himself of the
use of the microscope, and discovered something of the anatomical
character we afterwards demonstrated.
It would be useless to enumerate all the fugitive papers scatter-
ed through the ephemeral publications of the last and present cen-
tury, as they contain nothing for which we have not credited those
we have mentioned.
During the ascension of 1817, we entered into the investigation
with all the enthusiasm it could inspire, and contemplated it in
every aspect we could place it. When the time for observation
had nearly expired, we were mortified to find that we were not
much nearer a definite conclusion than we were in 1783, when the
subject first attracted our attention. We now perceived the cause
of our failure, and determined that, should there occur another ascen-
sion in our time, to avail ourselves of the power of magnifiers, and
prosecute the inquiry under more favourable auspices.
As our professional avocations would not permit us to devote
our whole time to the pursuit, it became necessary to call in the
aid of a colleague whose knowledge of entomology, and industry
could be relied on. These qualifications were found and well ex-
emplified in Mr. Gideon B. Smith. Should our labours reflect any
light on so obscure a subject, the credit is equally due to him.
As we have adopted the old Roman name locusta, and rejected
the modern word cicada, it behoves us to assign our reasons for
dissenting from modern naturalists. It must have occurred to
the votaries of natural history, that they are often met by too
great a propensity to generalise, and therefore to crowd incon-
gruous articles into the same genus. While it seems to promote
order and facilitate study, it sometimes operates at the expense
of accuracy, leaving some varieties undefined or imperfectly
described. If we are not deceived, the sequel will show that
this remark applies emphatically to the locust. Although it is
exclusively an American insect, it has been identified with a
species of another genus that belongs to the Eastern and Southern
continents. It has been unnaturally forced into the genus Gryllus,
and thus associated with the numerous varieties of the cicadas, to
which it bears some analogies, while many of its principal charac-
teristics are at variance with the whole tribe. It will therefore
appear, upon a further investigation, that foreign naturalists, (who
knew it only by tradition) have conceived a very imperfect con-
ception of its true character.
An inquiry into its anatomy and physiology will shew, that we
cannot run a parallel through the two genera, nor identify the lo-
cust with any one variety of either.
The genus Gryllus belongs to the fifth class of animals, called
Insecta. It comprehends those that breathe through lateral spiracles ,
and whose skins are bony, and covered with hair. They belong to
the second order, Hemiptera, with semi-crustaceous wings, and snout
inflected. The antennas are cetaceous and bristle shaped, with legs
formed for leaping. This definition embraces the whole tribe of
cicadse, which consists of grasshoppers, treehoppers and crickets;
and it is very natural (from a mere prima facie resemblance,)
that naturalists should have coupled them together. Hence
Linnseus denominated the American locust, Cicada Septemdecima ;
but Fabricius, sensible of some discrepancy he has not explained,
proposed a subgenus, which he denominated Tettigonia. This only
evades the difficulty, as it is the substitution of a Greek for a Latin
6
substantive ; the word Terr/I being synonymous with cicada. Those
great masters have been imitated by all their successors, and have
taken the Gnjllus J\ligratorius, the great architype of the cicadas,
as their pattern. This great monarch of the genus has given the
law to all others, not only to his own subjects, but the whole sci-
ence of entomology, where the faintest similitude can be found. In
common parlance and scientific writings, we find the same error. His
history presents a melancholy retrospect of national waste, and his
return is held up in terror to the Eastern and Southern continents.
His flights are marked through states and empires, by his devasta-
tions of the vegetable kingdom, and his name is coupled with pesti-
lence and famine, two of the great scourges of the human race.
He constituted one of the seven plagues of JEgypt, and was threa-
tened as a vindictive visilation by the prophet Joel. The only
atonement he has made for all the miseries he has inflicted, is the
precarious subsistence he afforded (together with wild honey) to
John the Baptist, in his journey through the wilderness.
It would not be possible at this remote period, to ascertain the
precise sense in which the Romans entertained the words locusta
and cicada. They employed both, but there is no word in the
Greek synonymous with locusta, more than is conveyed by T f rr;|;
and they must either have intended to designate two different in-
sects, or, with the moderns, applied the word locusta to the larger,
and cicada to the smaller varieties of that numerous genus.
A brief comparison will so contract the two genera, that our
reasons for separating them will, we think, be conclusive.
The cicadae are herbivorous, voracious and highly destructive,
while the locust can scarcely be said to subsist on vegetable matter.
They have no teeth nor mandibles, and in the proper sense, no
mouth. It imbibes its aliment by an apparatus that belongs to none
of the cicadae. The cicadae have jaws and teeth which arm them
with the power of destruction to the vegetable kingdom. We
were lately favoured with a fine opportunity of comparing the
great monarch of the cicadae with our locust. A perfect specimen,
male and female, of the Gryllus Migratorius, brought from -(Egypt
by Mr. Mendez I. Cohen, was furnished for inspection by Doctor
Joshua I. Cohen, and minutely compared. They are perfect cicadse
on the largest scale, with large, long wings that cover their whole
body, like a long frock coat, which enable them to fly rapidly, and
to a great distance. Their legs are powerful, and they can leap
also to a long distance, while the spindle shanks of the locust do
not permit such an action, and it is obliged to elevate itself prin-
cipally by its wings, having no lever legs to raise it perpendicu-
larly. While the cicadse elevate themselves in a perpendicular
line quickly, the locust can only raise itself slowly, horizontally.
The cicadae breed annually: the locust once in seventeen years.
The imaginary resemblance of the notes of the cicadse and lo-
cust, have led some to identify them. Such a notion (if it be
drawn from a comparison with the cicadae of Greece) is too meta-
phorical for a rationale. While it is admitted there is a resem-
blance in the construction of their vocal organs, we cannot claim
for the American songster a note that can be dignified with the epi-
thet musical. The cicadse of Greece must have been highly gifted
with musical powers, to have been celebrated by Homer, who
compares the strains of his orators to the sweetness of their notes.
How differently would the ear of the imperial poet have decided,
if he had been condemned to listen to the monotonous, protracted
twang of the American locust! He would have been as much
pleased with the scraping of a scissor grinder, or the grating of a
file. There are a few of our cicadae whose notes do not fall un-
gratefully on the ear, but most of them, compare literally with
the rauca cicada of Virgil, which could not have been intended for
a compliment.
The male only issues a note, which is the signal of adult age,
and is immediately followed by flight, in search of a mate. It has
been variously and very erroneously represented, both as to its
suavity and compass. If we except a slight variation, when the
insect is disturbed or driven from its place, (when it is louder and
more obstreperous,) it is single, but rises and falls through the gra-
dations ; crescendo, minuendo et cadendo. It has been likened to
8
the sounds of several musical instruments, but cannot be identified
with any. A duet, with the bass of a small organ, and a Jeicsharp,
(or rather Jawsharp, as there was probably no such instrument
among the Jews,) is the best imitation we can conceive.
The note can be heard, in a clear, calm atmosphere, threeorjour
hundred yards, but is not so astounding as it has been represented,
scarcely interrupting colloquial intercourse. When thousands unite
in the same choir, the universal din seems to compose a musical
atmosphere, upon which all other sounds float unmolested. The
note is never heard between the setting and rising sun. High winds
and cloudy weather repress, but do not silence it. A damp air
lessens its shrillness, and the number of songsters. Heavy or long
continued rains put a period to the whole process; but it is re-
sumed at the return of the rays of the sun ; and no sooner is the
water evaporated from the earth and surrounding foliage, than the
whole choir is heard in full glee. While the note is issuing, a mi-
nute inspection perceives a tremblous motion of the body, vibrating
under the impulse of the air in the musical cavities, and if the body
be touched it is still more evident. This will be better understood
when the whole apparatus shall have been described.
The external appearance of the full grown locust bears a strong
resemblance to the common horsefly* It is from an inch and a
quarter to an inch and three quarters long, and from three eighths to
half an inch in diameter, at the largest part of the body, and, in-
cluding the wings, from an inch and a half to an inch and Jive eighths.
The body is black, except the Jour rings that run transversely over
it, two large and two smaller, all tipped with orange.
The shape of the head is a good miniature picture of the head of
the elephant.
The eyes are red, though a few are black, and very prominent,
which increases their visual power, while it contracts its sphere,
which is limited to less than two Jeet, as may be demonstrated by
removing them beyond that distance from any object to which they
* Hyppobosca Equina.
9
are attached. Probably we have given them more power than
they possess, and we think it will be found they cannot see so far.
Their capacity for keen vision is vastly increased by the almost
incalculable number of lenses, with which the eye is supplied ; and
those so convex that objects invisible, unless through a microscope
that magnifies a hundred andfijty thousand, is clear to them. With
one that magnified four hundred and ninety thousand, we counted
the lenses with sufficient accuracy, and after repeated trials, came
to the conclusion, that there were ten thousand two hundred, not
many more or less. This mechanism gives the power of seeing in
all possible directions, and we will presently perceive how important
it is to the economy of the insect.
We have already alluded to the peculiar mechanism of the in-
struments by which the locust imbibes its aliment, so different from
those of the cicada?. They are exceedingly minute, and on a su-
perficial view, unappropriated ; but with a fine glass, their office is
designated at once.
They seek nourishment that is always present and ready, pre-
pared for the instruments through which they are to receive it.
The exhalation from vegetable barks forms their entire subsistence.
This they probably could not find without exquisitely keen vision,
as they have no olfactory nerves, that can be demonstrated.
We are, nevertheless, not to infer positively that they can neither
hear nor smell. We must search for another apparatus to find
the conduit of their nutriment. The antennae, we have re-
marked, are bristle shaped, standing between the eyes and the
rostrum or beak which furnishes the avenue through which the
nourishment is conveyed. It is in this sense only that the locust
can be said to have a mouth. There are three exquisitely fine hairs
appended to its extreme points, by which, through a high magnify-
ing power, we see them distinctly feeding on the dewy exhalation
of vegetable barks a material that may be compared to the in-
sensible perspiration of the animal body ; the insensible perspiration
of the vegetable skin. Although we cannot demonstrate that they
are tubular, they probably act by capillary attraction. The exquisite
2
10
tenuity of the exhalation from tender vegetable barks is such, that
the imagination can scarcely paint, and never could dream of it,
without the finest glasses. If it were possible, it might bear some
faint resemblance to the fracture of a diamond of the first water,
bespangled into myriads of chrystals!
There are two varieties of the decem septima, but only as to size
or magnitude. The minor tribe constitutes about, a hundredth part
of the whole race. We find the smaller at the same time and in
the same places with the larger variety, and all their organs and
habits the same. As we very seldom find any of an intermediate
size, it may be a question whether there is any sexual intercourse
between them ? The negative would seem to argue the violation of
a law of nature. They are about seven eighths of an inch long,
and five tenths in diameter.
Although the locust has received its distinctive appellation from
tbe singularity of its appearance once in seventeen years, and uni-
form experience confirms it, there, are still some who fancy they
have found exceptions to this law of nature. The want of obser-
vation, and too much credulity in popular rumour, has led them
into this error.
They do not appear at the same time over the whole area of
their nativity, but cover the whole ground by the same family once
in seventeen years, comprising others that sometimes intervene,
both having inhabited the same grounds since they were created.
Although all the families are uniform in their ascension, in time and
place, there may be two generations in the same place oftener than
once in seventeen years, because they were so located originally.
Such occurrences have confounded and deceived many, and made
them sceptics. Some examples within our own observation (and
we could adduce many more) will solve the problem. A part of
Virginia and Maryland will be sufficient. Here two families occu-
py the same grounds on each side of the Potomac river a part of
Loudon county on the South, and a part of Montgomery on the
north, or Maryland side, compose one section, while Fauquier
county, in Virginia, that lies adjacent to Loudon, form part of ano-
11
ther section that runs into Loudon. It is for this reason that we
find the locust twice in Loudon, at intervals of eight and nine years,
because they form two distinct generations, and will probably re-
main so forever, each experiencing its own decem septennial ascen-
sion.
It would be as tedious as it would be unprofitable to detail the
periods of ascension in every part of the continent, where they are
known to have appeared; but as we desire to satisfy all who feel
an interest in the matter, w r e will add a few examples of the chro-
nology of their appearance in such places as we are properly ad-
vised of. Our inquiries on this head have not been as extensive as we
could have desired, but as much so as are deemed necessary for our
purpose. We give them in the promiscuous order we received them.
They appeared in Louisiana in 1829. We have no accounts from
Florida, where they must have been seen. They have not been found
(that we are aware of) in Mexico, nor in any other South American
province. They appeared at Galliopolis, in Ohio, in 1821, and in
Muskingum in 1829 in part of South Carolina and Georgia in
1817 and 1834 in Middlesex county, in Jersey, in 1826 in parts
of Pennsylvania, west of the mountains, in 1832 in Massachu-
setts, near Fall's River, in 1834 and in the greater part of Mary-
land in 1749, 1766, 1783, 1800, 1817 and 1834. We have no
account from North Carolina, but they must have appeared there,
as they have been found in all the adjacent states. We are at a still
greater loss for information from the northern and eastern parts of
the continent. We have none from the states of New York, Con-
necticut, Vermont, Maine, or New Hampshire, though they were
first described in Massachusetts. It is most probable they pervade
the whole continent, though it is possible the low temperature of
the far north may draw a line beyond which they cannot exist.
This remark, nevertheless, is rather intended to apply to the Cana-
das, New Brunswick and Nova Scotia, where, (if they ever were
seen) there is no tradition. Future observations must decide the
extent of their nativity.
It has been supposed that there are certain localities that the lo-
12
cust instinctively avoids, though they are sometimes seen there.
This hypothesis supposes that such places are unfit for the purpo-
ses of propagation, and is true in part, but requires some explana-
tion. Instinct always directs it to such places as are best adapted
to its economy. We find it on the mountain tops, and in the plains,
where there is a soil to rear trees and shrubs, without which there
could be no place to deposite their eggs. They are equally re-
pelled by a rocky and a sandy soil, in neither of which they could
find subsistence, or construct their habitations. They do not bur-
row in a soil usually saturated with water, on the shores of water
courses, nor the margins of meadows or marshes ; though we have
them down the declivities of hills, till they are repelled by a cold,
damp soil.
As we have given some imperfect description of the note of the
locust, \ve must attempt to describe the instruments by which it is
produced a task the more difficult because we cannot judge very
accurately by comparing them with any thing. There is some-
thing in vocal music, the result of living animal matter, that art
cannot aspire to, nor scarcely imitate.
If we view the body externally, we perceive, under the shoulders
of the wings, a small, delicate membrane, nearly triangular, and con-
vex, with fine, long ridges, or ribs running over it. It resembles a
small shell, and is stretched over a cavity, in the chest, like the head
of a drum, each lower angle being intimately connected with a fasci-
culus of muscular fibres. There are two scales, one on each side of
the thorax, firmly attached above and below. By bending the body
backwards, they are elevated, and expose two larger cavities, covered
by an exquisitely fine, silk-like membrane. Those cavities are con-
nected with those under the musical membranes, and are the reservoirs
of air, with which they are filled. The upper ends of fasciculi of
muscular fibres, are tied doicn to the inner centre of the breast bone,
and the lower ends pass through the sides of the posterior cavity of
the chest, attached by a ligament, to the inferior angle of the musical
membrane, forming together, a triangle, and span the chest like the
rafters oj a house.
13
The musical process begins with the action of the muscular
fibres, but they do not finish it. The motions of the fibres puts the
membrane in motion while it is floating in air, constantly supplied
by the reservoirs. The motions of the muscular fibres and mem-
branes are almost inconceivably rapid, and may be compared to the
wings of a fly, poised in air, which seem to stand still, because the
naked eye cannot follow their velocity. Here the sense of touch
discovers that which the eye cannot perceive. If we apply the
point of a fine needle to the sides of the insect, a jarring sensation
is felt, like that imparted by filing a thin plate of steel. By press-
ing on the fasciculi the notes cease. By cutting one of the fasci-
culi the music ceases on that side, but continues on the other. By
dividing both fasciculi, we put an end to all sound. By pressing
on the fasciculi the note ceases, and if we press the air out of
of the reservoirs, the same effect is produced. There is still some-
thing wanted to perfect the musical process an avenue to the ex-
ternal air. For this purpose there are two small apertures, one on
each side, near the insertion of the inner wings, between them and
the tympanum. They are capable of dilatation and contraction, at
pleasure, and receive as much air as is necessary to fill and modu-
late the note.
When we were dissecting and separating the parts composing the
musical apparatus, we were not aware that we had been anticipated
by the celebrated Reamur, in his description of those of the cica-
dae, which bear a strong resemblance to those of the locust,
The special economy and character of the locust next demand
our consideration. We must trace it from its ascent to its death,
when it is soon succeeded by a new generation.
It first appears at the surface of the earth, in the pupa or grub
Jorm, preparatory to the chrysalis state almost defenceless and
very imperfect It is discovered in Maryland on or about the tenth
of April. We found it on that day, at the four successive ascensions
of 1783, 1800, 1817 and 1834. We do not assert that they do
not appear sooner or later, nor that they arise at the same time in
all other places. They are usually discovered by the hogs rooting
14
for them, and eating them with avidity, and hence we do not see
them otherwise, unless we break the upper stratum of the soil. By
removing it about a quarter of an inch deep, we discover a great
number of holes about Jive eighths of an inch in diameter, resem-
bling auger holes, six, eight, or ten inches apart, according to the
facilities of entrance when the young were hatched, and extending
downwards six, eight, ten, and sometimes twelve inches. Proceed-
ing downwards, the pupa is found at the bottom, and appears to be
well formed, though all its parts are not entirely unfolded. This
is more remarkable in the wings, which look more like appenda-
ges than real wings, lying close to the body, and unfit for use.
This imperfect state of the wings seems necessary to the safety of
the body, as in a more developed form, they would operate as an
impediment to the ascent, and accordingly, we find that, as soon as
they emerge into a warmer and dryer atmosphere, they become
harder and begin to expand. When the pupa first appears the
body is fresh, soft, moist and so tender, that it is easily injured,
while the extremities are hard and fit to work their upward course,
and creep to such objects as they instinctively seek. The whole
external appearance, as well as the occupation of the pupa, indi-
cate a very material, recent change; that they have either sloughed
or undergone some transformation preparatory to the chrysalis
state, the next in order of completion. We have, moreover, other
reasons for concluding that other important functional changes now
follow. During its residence in the earth, the pupa is in a state of
gradual, but slow growth, without any change, except its incre-
ment. They have been found, at various periods after their de-
scent, covered with the same brown shell that always invests them,
till the transformation they undergo, when they become pupae.
Mr. Samuel Feast, an intelligent gardener and naturalist, dug them
from the earth, one and two years before the last ascension, in this
form, but not completely grown. Mr. Ellis Thomas found them
in this state in his garden eight years after their descent, nearly half
grown. These facts clearly demonstrate that they require the
whole time of their subterraneous existence to complete their
15
growth, and that the grub or pupa form is not assumed till a short
time before they are found at the surface of the earth. While the
insect is under ground, gradually acquiring its growth, it performs
the functions of digestion and excrementition, we find it furnished
with a strait intestinal tube, the upper part of which is expanded
into a wider receptacle, and seems to answer for a stomach. When
the pupa leaves the ground and the body is almost matured, these
organs seem to be almost obliterated, as we find only a wasted
membrane that can perform no function, a mere remnant of former
vitality. As little or no growth is required after the pupa state,
there is no necessity for a stomach, and during the fleeting existence
of the insect in open air, no excrementitious matter can be found.
The cavity occupied by the digestive organs is now filled by the
seminal fluid in the male and the eggs in the female.
The time between the discovery of the pupa, and its final exit
from the earth, is spent in maturing its skin, and acquiring strength
to fit it for more active operations, to fulfil its destination.
During the warmer hours of the day, it is seen peeping from its
cell, seeming to enjoy the warm, fresh air. At twilight, or if the
temperature fall during the day, they retire to their chambers. In
this imperfect state, their progress is slow, and they are unfit to
inhabit the open air for eight or ten days. They then cast off their
slough, which finishes the short-lived chrysalis state, and become
perfect locusts in twenty four hours, and sometime sooner their
progress depending, in some degree, on the temperature of the at-
mosphere.
If we descend to the bottom of their chambers, we find them (as
already remarked) six, eight, and sometimes ten or twelve inches
deep; but as it is generally supposed that their residence is more
profound, it is necessary to shew that this is an error, during their
pupa state at least. To determine this question, and some others
no better settled, we selected for our field of observation, an
ancient oak grove of several acres. The upper stratum is a stiff
loam, mixed with some gravel, and inclining, in places, to sand At
a depth of from two to three feet there is a stratum of pale blue
16
clay, rather compact, and well formed to retain any impression it
might receive; and as the holes are always filled below with earth
removed from above, through their whole course, their depth was
easily ascertained. They were uniformly found filled to within
six or eight inches of the top, with earth from which all vegetable
matter had been extracted, and packed so hard that their depth
could not be mistaken. In no case could we trace them to the
blue stratum of clay below. From this fact it is clear that this is
the utmost depth of their domicil in the latter stage of their sub-
terraneous pilgrimage. All that seems to be required for the safety
of the insect under ground is a temperature congenial to its degree
of vitality; and although they descend deeper in search of ali-
ment, previous to the assumption of the pupa state, it is clear there
can be no necessity for it after it. The late Mr. William Patter-
son, of this city, saw them three feet below the surface of the
earth, when they were very small, not quite three years old. The
extent of the descent in this state is also confirmed by inspecting the
bottom of their chambers, where we always find a certain quantity
of refuse matter, hard and compact, in the form of a plug. This is
neither of the consistence or colour of the surrounding soil, but fecal
matter, strongly cemented, stiffer and more clay-like. It would ap-
pear, from these facts and reasoning, as a consequence, that the ob-
jection so often made to Jihe superficial descent of the locust is
futile. It has been remarked that the ground, during our cold win-
ters, sometimes freezes below the depth of eight or ten inches. Before
the chambers are constructed, they can descend as low as their in-
stinct directs them to be agreeable, and certainly do, as we never
find any diminution of numbers at any ascension after the hardest
winters. If we examine the construction of the chambers which
seem to be intended to protect them, in their most tender state, we
find them ample and admirably formed for that purpose. The walls
are thick and strong, cemented so firmly that water will not pene-
trate them, nor heat easily escape, preserving nearly a uniform
temperature.
The superficial descent of the locust, and the construction of its
17
temporary dwelling, is analogous to the habits of other animals,
especially the hybirnating, such as alligators, tortoises, frogs and
others which immerse themselves beneath their natural element
into a uniform temperature, merely high enough to be susceptible
of excitement by the vernal return of heat. Although the locust
does not lie torpid, instinct directs it to provide for its own preser-
vation by insuring a steady temperature that answers all the pur-
poses of its economy.
Is not the migration of birds regulated by the same principle?
They instinctively seek more congenial climes to evade the seda-
tive influence of cold.
A more minute account of those apartments will shew how well
they are adapted to the purposes of self-preservation, and how
much better they are directed by instinct than they could have been
by any contrivance human reason could invent.
On a first view of the external opening of the chambers we
would suppose that they run in a perpendicular direction; but we
find them deviating more or less: some running horizontally, others
at obtuse or acute angles, while some form entire circles. All
these varieties, and their modifications, are found where there is no
impediment to a perpendicular ascent, which they meet some-
times. They come up occasionally under the roots of trees, floors,
logs, stones and pavements laid since their descent. In such cases
they pursue any course by which they can reach the surface; but
they sometimes fail from the distance they have to travel. We
found many that had perished under a brick pavement that had
been laid over them after their descent.
The roofs of their tenements are neatly arched, and so firmly
cemented that water is never found in them, though all th6 sur-
rounding grounds are overflowed and perfectly saturated. This
defence against an element that would be destructive, is to be at-
tributed to the workmanship of the cells, the interior of which are
varnished with a secretion that seals them hermetically, from bot-
tom to top, and makes them water proof. The locust is not singu-
lar in this provision against inundation and drowning. The cray-
18
fish,* with other amphibious shellfish, and some insects, build houses
along the margins of water courses, where the soil is too wet and
cold, and rear them above tide water. They resemble small chim-
nies, and are so firmly cemented that water will not penetrate their
walls. The glutinous secretion they employ resembles the slime on
the bodies of snails, which seems to be used for the same purpose.
When the locust takes its final leave of its cell, it selects the still-
est and most private hour, about day-break, to guard against the
accidents to which it is liable in so weak and defenceless a state,
till it can fly. Some cannot divest themselves of their sloughs
under a cold damp atmosphere. Others ascend at so great a dis-
tance from any object by which they can climb up, that they perish
before they can get the benefit of the sun. Great numbers are
devoured by hogs, squirrels, all kinds of poultry and birds, which
live and fatten on them.
No sooner has the pupa issued from the earth than we perceive
a change which leads almost immediately to the divestment of its
coat. It becomes browner and harder, more particularly on the
back, between the head and wings. The latter are still more de-
veloped, but wear a delicate, silk-like appearance. The wings
become amber, and the wing bones assume a bright orange colour.
The process by which they extricate themselves from the slough
is slow at first, though soon finished. It is similar to the shedding
of a crab, except the part through which the body is drawn from
the shell. That of the crab open laterally at the side, opposite
the eyes and mouth the locust longitudinally, in the middle of the
back. They are both disengaged by the muscles of their legs,
with their claws constantly in motion till the process is finished.
We saw the first that had sloughed on the eighteenth of May, a
few on the nineteenth, and from that time they multiplied almost
incalculably, till the twenty fifth. From that day till the twenty
third of June the numbers declined in the same ratio. On the
fourth of July we found very few, and on the fifth one.
We found the first pair in sexual union on the twenty fjth of May,
* Cancer Astacus.
19
but this was considered precocious, as we could find no others till
the first of June. On the third we saw a considerable number,
which increased daily, and then declined. On the thirteenth we
found only a solitary instance of the last melancholy note of an
expiring race, to be heard no more for seventeen years.
On the fourth of June we found that a few boughs had been
operated on by the female, and one on the first. The greatest de-
posite of eggs was on the tenth, and declined till the sixteenth,
when we found only one.
The principal male organ of generation lies concealed in a
sheathe at the lower extremity of the abdomen, from which it
scarcely protrudes. When they come sexually together, the fe-
male embraces the male, and holds him in close contact, by means
of a hook on each side, turned backwards, and he is immoveable
till the process of impregnation is finished. The union continues
from fifteen to eighteen hours. When they separate the female is
frequently seen flying away with half the male, broken off in the
middle region of his body.
The male and female survive only two or three days after they
have performed their respective parts in the process of generation.
The male dies first, and the female lives the same time after the
deposition of her eggs. They emaciate-rapidly, and at their death
are skeletons as light and void of substance as the exuviae cast off
by the crysalis. The body is without muscular substance, the ab-
domen empty, and no moisture to be found but a little in the head
and chest.
The most remarkable parts of this extraordinary insect are those
of the female the machinery by which she works in effecting a
depository for her eggs. The ovipositor is lodged in a groove, and
lies at the terminating ring of the abdomen, and the oviduct passes
through its centre. When not in use, it is concealed, except a
minute point at its lower extremity. It is composed of three dis-
tinct pieces, connected at the sides by the nicest tongue and groove,
by which the two side pieces play up and down upon the centrepiece.
The material of these parts is similar in appearance to tortoise
so
shell, dark brown and elastic, but more brittle, and bent to a cer-
tain extent, fractures short, like a pipe stem. The edges and points
of the side pieces are serrated, Jorming perfect saws, while their flat-
tened surfaces form rasps equally perfect. When the instrument is
protruded and examined by the microscope, the denticulations of
the saws are clearly perceived. There are fijteen teeth on each
side, symmetrically arranged, tapering aw r ay in fineness towards the
point, where we find three or four more, so small that it is scarcely
possible to determine, by the best glasses, whether there are three
or four. In some there appeared to be three, in others four.
Previous to the application of the instruments, the female de-
posites a fluid on the part to be operated on. It seems to be in-
tended as an emollient, and probably to mark the extent of her
work. It is a secretion from the inner surface of the oviduct, so
exquisitely fine that it is only to be seen by a fine glass. The prac-
tice of softening the place of deposite for eggs is not uncommon
among insects and amphibious animals. Some of the tortoises use
their urine to soften the surface of the ground, that they may ex-
cavate the hard soil with more ease, and deposite their eggs
quicker.
When the female selects a limb, she goes formally and indus-
triously to work, and soon finishes it. She raises her body, ex-
tends the point of the instrument, and with her whole weight pierces
the bark with the upper point of the centre piece or chisel, which is
like the flattened point oj a thumb lancet, making way for the side
pieces or saws. Though the puncture is very minute, scarcely
perceptible a it is sufficient for a place of entry, and a quick sawing
motion now commences, and continues till the apertures are large
enough to admit the other side piece, which follows with the like
motion. As soon as the blade point is fairly inserted, say the
twelfth of an inch, she presses on the part attached to her body,
and then, by a lever, raises the ends of the divided fibre ; she then
adjusts the three different parts of the instrument, forming two saws
by its edges, two rasps by its flattened sides, and a perforator or chisel
by its point. The uses of the perforator and saws are easily per-
81
ceived, but the design of the rasps would not be discovered with-
out seeing and closely observing the progress of the operation in
its different stages. They seem to be intended to comminute and
divide the rough ligneous fibres furrowed up by the saws, and thus
prepare a softer and smoother bed for the eggs. While the female
is sawing away the sides, and rasping up the ends of the fibres
below, she withdraws the instrument occasionally and reinserts it,
till she shall have penetrated the full length of the incision, in a
direction obliquely downwards, towards the pith, which is never
touched, because it would not be a proper nidus, and a deeper cut
would weaken the ligneous fibre, and it would be easier broken.
As soon as the opening is made deep enough, she enlarges it exter-
nally, by plying the saws along its sides and the rasps to the top
and bottom. She now withdraws the instrument for a moment,
and reinserts it to its full length, depositing two eggs in quick suc-
cession. She withdraws it again, reinserts it, and deposites two
more, till she shall have laid from ten to twenty, but never an odd
number. The number in a single fissure depends on the size of the
perforation, and that on the bough which may be crooked, knotty,
or otherwise defective 3 or occasionally rotten in the middle. The
eggs are set uniformly in two rows, close together, their ends in-
clining downwards. They are one twelfth of an inch long, and
one sixteenth in diameter, tapering to an obtuse point. They are
of a pearl-like white. She is about fifteen minutes in preparing a
single nidus and depositing the eggs; but it is not uncommon for
her to make fifteen or twenty fissures in the same limb, more or less,
according to its fitness. She frequently shifts from one limb to
another, and from tree to tree, before she can deposite all her eggs,
the whole number of which varies from four to five hundred. She
seldom selects a limb more than a quarter of an inch in diameter,
though often a smaller one. Both the upper and lower sides are
sometimes perforated, but never directly opposite to each other.
The age and texture of the wood seem to be disregarded. A
thorny or abruptly crooked bough seems to annoy her in searching
for a place of entry. We were amused by the maneouvres and
apparent disappointment of several that had lighted upon a flourish-
ing aurelia spinatu. Three of them left it precipitately after light-
ing on ten or a dozen branches, which they inspected closely, till
one more persevering than the rest, found a single fit place of de-
posite, finished her work and departed.
There are but few trees and shrubs not invaded, and the larger
under vines are not exempted. The younger rose and raspberry
bushes were frequently perforated immediately above the ground,
where the stock was large enough. We found no forest tree un-
touched, except the pine, with the whole tiribinthenate class, ex-
cept a few of the white cedar.*
We see the perfection of instinct in the selection of boughs of a
small dimension. Those that are smaller are more tender and suc-
culent, affording a milder and more copious nourishment for the
embryo, while a larger size could not be well operated on on ac-
count of their larger growth and hardness. As a considerable force
is required to introduce the instrument, it is necessary that the fe-
male should grasp the whole circumference of the limb, to steady
herself, and concentrate her strength. If she were to attempt a
larger limb, her legs would be so much distended that her muscu-
lar power would be diminished, and she could not take a firm hold
with her claws.
The punctured branches decay and die after the young have left
them, and we have some evidence of the injury they have received
before that time. The leaves becomes yellow from the failure of
a perfect circulation, the medium of which is cut off, or much im-
paired. They do not fall off immediately, unless broken by a
heavy wind, but hang by the bark, which is more pliant and tough-
er than the liburnum in which the eggs are lodged.
The great number of dead boughs we perceive after an ascen-
sion, that give a chequered appearance to our groves and forests,
only contrast living green with dead yellow, with little or no inju-
ry. Old forest trees and orchards suffer but little, and some of
them that are very luxuriant seem to improve under the pruning
knife of the locust. The younger articles of the nursery, and or-
* Cupressus Thycides.
23
namental shrubbery, are the principal sufferers. The grafts or
buds of the last summer, grown only a few feet, with a single strait
stem, are destroyed, or if, by chance, a bud be left beneath the
wound, a year's growth is lost, and the beauty of its form spoiled.
We must now trace the progress of the embryo from its incuba-
tion till it descends to its long subterraneous abode, where we
found it.
The time at which the eggs are fit for deposite is forty eight
hours after impregnation, or within a fraction of that time. They
are so transparent, that we can see indistinctly the features of the
future insect through the shell, and with a good glass they are still
more visible. The shell wears a pellucid, membranous appear-
ance; but notwithstanding their apparent delicacy, they retain their
contents longer than other eggs either of insects or birds. They
hatch in fifty two days. We saw a deposite on the fifth of June,
and marked the spot, and witnessed the parturient process on the
twenty eighth of July. On the fifteenth day after the deposite we
discovered a manifest change of colour and form in the eggs, which
increased gradually till the embryo assumed the form of a worm,
without legs, and a thicker cream colour succeeded to the shining,
pearl-like white. Instead of the previous well-defined shape, it
now becomes crooked, and the form of the head is obvious, while
the body takes on the form of a silk-worm wrapped up, in a cream-
coloured cocoon. The most distinct feature is now the eye, which
is well defined ten days before the shell is broken. The rings of
the body, and the legs are easily distinguished, laid close to the
abdomen. Immediately before birth a distinct motion is to be ob-
served in the. insect in the eggs, resembling the jerking of the tails of
butterflies and moths, in the chrysalis state, when they are disturbed.
We took several nests from a bough marked for observation at the
exact, time of maturity, and soon perceived the signs of parturition.
We placed some of the eggs between two scales of mica, and ap-
plied the microscope. The power of the glass brought upwards
f fifty within its focus, and the whole process was clear and satis-
factory. Temperature exerts a considerable influence on the pro-
24
cess. It is accelerated by heat, and retarded by a low temperature.
Those we held in our hands hatched sooner than those on the limbs
at the temperature of the air. The act of delivery differs but litlle
from that of the chrysalis. A rupture of the fetal membrane cover-
ing the back is first effected by muscular motion. The insect
draws its body upwards, and seems to swell, whilst it throws its
lower extremities to and fro, labouring in all possible attitudes to
extricate itself. It draws out its head slowly, disengages its fore
legs, and in a few minutes its whole body. The moment it is set
at liberty it begins to caper as if it were in a new state of existence,
seeming to exult in its delivery. For a moment it seems to be at a
loss what to do, till instinct begins to operate and directs it to its
proper element. As soon as it is freed from its shell it falls to the
ground. It does not run nor creep down the body of the tree, nor
cast itself off precipitately; but runs to the side of the limb,
loosens its claws, and falls to the ground by an instinctive rule, for
from whatsoever height it may have descended, it sustains no inju-
ry. When it inters itself it descends by the side of some vegeta-
ble root, which is its first and only aliment under ground.
In this state it is blind, and acts by the sense of touch, and feels
its way downward by its antennas. Although its eyes are promi-
nent, they are covered by an opaque film, through which the rays
of light cannot pass. What would be the use of vision to an in-
sect destined to dwell in darkness sixteen years and nine months ?
Perfectly formed eyes would be an incumbrance, while the mem-
brane that invests them defends them from injuries in passing
through a grass-irritating medium. In this state the young insect
shews, also, the rudiments of wings, but they are not unfolded,
because they are not wanted. What would be their use when
adult age, the only time they could use them, is almost as distant
as that of a child born at the same time ? While it has fit for use
all the parts required beneath the soil, it is restrained in the use of
others till it shall have passed through a long infancy, a short ado-
lescence, and puts on the toga virilis at seventeen.
25
We must be indulged while we draw a further comparison be-
tween the newly born progeny and the pupa as we find it sixteen
years and nine months after: the odd three months, from its ap-
pearance at the surface of the earth till its death in the adult and
last state, completing the whole circle.
When the young emerge from their native place, they are one
sixteenth oj an inch long, apparently, on a superficial view, nearly
perfect, but with some parts better developed than others. With
three pair of legs, one before and two behind, the former resemble
those of the pupa are strong and muscular, armed with hard,
sharp claws, while the latter are slender and more delicate, with
their hooks reversed, being intended for pushing, while the fore
legs are employed in pulling in the same direction, so that they
work together, assisting each other.
The antennae are longer in proportion than those of the pupa,
and the whole body longer in proportion to its diameter. The
whole body of the young locust is thickly covered with /iair,
which is more remarkable on the sides, tail and antennae. This
covering seems to furnish some defence against external impressions,
and keeps them warm in their tender, infantile state. The promi-
nences we find on the shoulders shew the rudiments of unfolded
wings, as in the pupa. The eyes are of a deep orange red colour.
The hooks of the claws incline to red. The snout is much longer
in proportion than that of the pupa, and lies flat in the chest. The
head seems longer, also, but this appearance is deceptive. It seems
to project considerably, and this gives it the appearance of the
ewer mouths of certain small fish, the upper lip only projecting,
and is only an extension of the skin beyond the extreme point of
the real head. This apparent deformity is subsequently adjusted
by the perfect developement of the other parts of the body. The
membraneous extension is found filled with a serous-like fluid that
resembles the fluid under the cuticle vesicated by Cantharides.
We have seen the dangers to which the locust was exposed till
it shook off its chrysalis form and was able to fly. They are few
and inconsiderable compared to those to which the fetal state is
26
liable. It is probable that not one third of the eggs come to per-
fection, and were it not for the myriads that are laid, there would be
a slender account of the next generation, and in not many more, the
whole race would be extinct. Besides the great numbers of eggs and
young picked from the boughs by woodpeckers and other birds, they
are constantly infested by legions of ants before and after they are
hatched. Even the little red species, the most diminutive of the
race, will shoulder the eggs and the young, and bear them off to
their cells. In all our researches we found them in battalions, sys-
tematically arrayed for wholesale plunder and devastation. They
are probably the most numerous of all the insects on our globe,
and are found in all nations and all latitudes.
The mode of subsistence in the earth, from the time the young
descends till it appears at the surface in the pupa state, does not
seem to have been conjectured. We have already suggested that
the young, when it falls to the ground, descends by the side of a
vegetable root. It seeks first a penetrable spot, and then the
fibrous roots of vegetables that insure its means of subsistence. It
moves along the particles of earth through those interstices that
are found in all soils, and furnish a passage to any necessary depth.
It does not dig a passage for which its tender limbs would be unfit,
and which is unnecessary from the constitution of the soil, if we
view it through a good glass. We find the particles loosely ag-
gregated, resembling heaps of stone, through which mice and rats
find their way with ease. The soil is more loosely connected by
the insertion of numerous small roots with which it is every where
intersected to a certain depth, and of which there are ten times as
many as could be seen by the naked eye. In all places they are
found attached to the tender fibrils of plants. When they are dis-
turbed or driven from them, they seek for others the moment they
are at liberty. This is their only aliment, not the substance of the
roots of plants, which they cannot divide and comminute without
teeth or jaws to use them, but the more aerial exhalation from their
surface. This well established fact would seem to account for the
slowness of their growth, and furnish a reason for so long a subter-
raneous residence.
21
We must devote a lew words to popular credulity, which has
circulated so many marvellous and idle tales of the venomous cha-
racter of this poor, defenceless insect. The very organism of the
locust refutes them all. It has no jaws, teeth, sting, or any other
instrument by which it can injure or annoy the most diminutive
insect no weapon, offensive or defensive. It cannot defend itself
against an ant or a fly. We have handled them, male and female,
time after time. We have irritated and mutilated them, but never
could provoke them to resentment.
As it is not probable that we shall witness the next ascension in
1851, we leave to our successors the task of filling up the void we
have left, and correcting our errors. We expect from th^m what
time and circumstance would not permit us to accomplish. We
do not know exactly the increment of the body from the time the
young descends into the earth till we discover the pupa at the sur-
face of the soil; though, from the facts stated, we think it may be
calculated without much inaccuracy. We have not had the means
of defining distinctly the period at which they begin to construct
their chambers, though it may be nearly approached by reasoning
from the facts we have mentioned. It is certain that no animal
builds a house for itself till it arrives at adult age. And, in fine,
although nothing was made in vain, we know not what link the
locust forms in the chain of animated nature.
Baltimore, November 19, 1834.
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