South America, the attacks of which are infinitely more serious
than those of the common flea. You will readily conjecture that I
am speaking of the celebrated _Chigoe_ or _Jiggers_, called also
_Nigua_, _Tungua_, and _Pique_[145], (_Pulex penetrans_,) one of the
direst personal pests with which the sins of man have been visited.
All disputes concerning the genus of this insect would have been
settled long before Swartz's time, (who first gave a satisfactory
description and figure of it, proving it to be a _Pulex_, as has been
observed above[146],) had success attended the patriotic attempt
of the Capuchin friar recorded by Walton in his _History of St.
Domingo_, who brought away with him from that island a colony of
these animals, which he permitted to establish themselves in one
of his feet; but unfortunately for himself, and for science, the
foot intrusted with the precious deposit mortified, was obliged to
be amputated, and with all its inhabitants committed to the waves.
According to Ulloa, and his opinion is confirmed by Jussieu, there
are two South American species of this mischievous insect. It is
described as generally attacking the feet and legs[147], getting,
without being felt, between the skin and the flesh, usually under
the nails of the toes, where it nidificates and lays its eggs;
and if timely attention be not paid to it, which, as it occasions
no other uneasiness than itching, (the sensation at first, I am
assured, is rather pleasing than otherwise,) is sometimes neglected,
it multiplies to such a degree, as to be attended by the most fatal
consequences, often, as in the above instance, rendering amputation
necessary, and sometimes causing death[148]. The female slaves in
the West Indies are frequently employed to extract these pests,
which they do with uncommon dexterity. Yarico, so celebrated in
prose and verse, performed this kind office for honest Ligon, who
says, in his _History of Barbadoes_, "I have had ten (Chegoes) taken
out of my feet in a morning, by the most unfortunate Yarico, an
Indian woman[149]." Humboldt observes, "that the whites born in the
torrid zone walk barefoot with impunity in the same apartment where
a European recently landed is exposed to the attack of this animal.
The _Nigua_ therefore distinguishes what the most delicate chemical
analysis could not distinguish, the cellular membrane and blood of a
European from those of a creole white[150]."
You have already, perhaps, been satiated with the account before
given of our enemies of the _Acarus_ tribe: there are a few, however,
which I could not with propriety introduce there, as they do not
take up their abode and breed in us, which nevertheless annoy us
considerably. One of these is a hexapod so minute, that, were it not
for the uncommon brilliancy of its colour, which is the most vivid
crimson that can be conceived, it would be quite invisible. It is
known by the name of the harvest-bug, (_Leptus autumnalis_,) and is
so called, I imagine, from its attacking the legs of the labourers
employed in the harvest, in the flesh of which it buries itself at
the root of the hairs, producing intolerable itching, attended by
inflammation and considerable tumours, and sometimes even occasioning
fevers[151].--A similar insect is found in Brazil, abounding in
the rainy season, particularly during the gleams of sunshine, or
fine days that intervene; as small as a point, and moving very
fast. These animals get upon the linen and cover it in a moment;
afterwards they insinuate themselves into the skin and occasion a
most intolerable itching. They are with difficulty extracted, and
leave behind them large livid tumours, which subside in a day or two.
An insect very tormenting to the wood-cutters and the settlers on
the Mosquito shore and the bay of Honduras, and called by them _the
doctor_, is thought to be synonymous with this[152].--More serious
consequences have been known to follow the bite of another mite
related to the above, if not the same species, common in Martinique,
and called there the _Bête rouge_. When our soldiers in camp were
attacked by this animal, dangerous ulcers succeeded the symptoms just
mentioned, which, in several cases, became so bad, that the limb
affected was obliged to be taken off[153].
I was once collecting insects in Norwood, near London, when my hands
were covered by a number of small hungry ticks, which were so greedy
after blood, that they penetrated deep into my flesh, giving me no
little pain; and it was not without difficulty that I extracted
them. I suspect that this was the dog-tick (_Ixodes Ricinus_) which
is often found on plants; but I am not certain, as I neglected to
examine it, my attention at that time being almost wholly given to
_Coleoptera_. Lyonnet seems to have been attacked, in one of his
entomological excursions, by the same or a similar insect, which he
broke, so firmly had it fixed itself, in endeavouring to extract it;
and he was obliged to lay open the place lest an abscess should be
formed[154]. But the worst of all the tick tribe is the American
(_Ixodes americanus_) described by Professor Kalm. This insect,
which is related to the preceding, is found in the woods of North
America, and is equally an enemy to man and beast. They are there
so infinitely numerous, that if you sit down upon the ground, or
upon the trunk of a tree, or walk with naked feet or legs, they will
cover you, and, plunging their serrated rostrum into the bare places
of the body, begin to suck your blood, going deeper and deeper till
they are half buried in the flesh. Though at first they occasion no
uneasiness, when they have thus made good their settlement, they
produce an intolerable itching, followed by acute pain and large
tumours. It is now extremely difficult to extract them, the animal
rather suffering itself to be pulled to pieces than let go its hold;
so that the rostrum and head being often left in the wound, produce
an inflammation and suppuration which render it deep and dangerous.
These ticks are at first very small, sometimes scarcely visible,
but by suction will swell themselves out till they are as big as
the end of one's finger, when they often fall to the ground of
themselves[155]. The serrated haustellum of the ticks, which, like
the barbed sting of a bee, cannot be extracted unless the animal
cooperates, is well worth your inspection; and the species which
infests our dogs is so common that you will have no difficulty in
procuring one for examination.
I have now introduced you to the principal insects of the _Aptera_
order of Linné, which, in spite of all his care and all his power,
assail the lord of the creation, and make him their food. You will
here, however, perhaps accuse me of omitting one very prominent
annoyer of our comfort and repose, which you think belongs to this
tribe--the bed-bug (_Cimex lectularius_). When you are a more practised
entomologist, you will see clearly that this, though it has no wings,
appertains to another order: nevertheless it may be introduced here
without impropriety. Though now too common and well known, in this
country it was formerly a rare insect. Had it not, two noble ladies,
mentioned by Mouffet, would scarcely have been thrown into such an
alarm by the appearance of bug-bites upon them; which, until their
fears were dispelled by their physician, who happened also to be a
naturalist, they considered as nothing less than symptoms of the
plague. Being shown the living cause of their fright, their fears gave
place to mirth and laughter[156]. Commerce, with many good things, has
also introduced amongst us many great evils, of which noxious insects
form no small part; and one of her worst presents were doubtless the
disgusting animals now before us. They seem, indeed, as the above
fact proves, to have been productive of greater alarm at first than
mischief, at least if we may judge from the change of name which took
place upon their becoming common. Their original English name was
_Chinche_ or _Wall-louse_[157]; and the term _Bug_, which is a Celtic
word, signifying a ghost or goblin, was applied to them after Ray's
time, most probably because they were considered as "terrors by
night[158]." But however horrible bugs may have been in the estimation
of some, or nauseating in that of others, many of the good people of
London seem to regard them with the greatest apathy, and take very
little pains to get rid of them; not generally, however, it is to be
hoped, to such an extent as the predecessor of a correspondent in
Nicholson's _Journal_, who found his house so dreadfully infested by
them, that it resembled the Banian hospital at Surat[159], all his
endeavours to destroy them being at first in vain. And no wonder; for,
as he learned from a neighbour, his predecessor would never suffer them
to be disturbed or his bedsteads to be removed, till, in the end, they
swarmed to an incredible degree, crawling up even the walls of his
drawing-room; and after his death millions were found in his bed and
chamber furniture[160].
The winged insects of the order to which the bed-bug belongs, often
inflict very painful wounds.--I was once attacked by a small species,
near _Cimex Nemorum_, L. (_Hylophila_, K.), which put me nearly to as
much torture as the sting of a wasp. The water boatman (_Notonecta
glauca_), an insect related to the _Cimicidæ_, which always swims
upon its back, made me suffer still more severely, as if I had been
burned, by the insertion of its rostrum; but the wound was not
followed by any inflammation; and long before me Willughby had made
the same discovery and observation[161]. St. Pierre, in his _Voyage
to Mauritius_, mentions a species of bug found in that island, the
bite of which is more venomous than the sting of a scorpion, and is
succeeded by a tumour as big as the egg of a pigeon, which continues
for four or five days. You are well acquainted with the history
and properties of the _Raia Torpedo_ and _Gymnotus electricus_;
but, I dare aver, have no idea that any _insect_ possesses their
extraordinary powers.--Yet I can assure you, upon good authority,
that _Reduvius serratus_, commonly known in the West Indies by the
name of the wheel-bug, can, like them, communicate an electric shock
to the person whose flesh it touches. The late Major-general Davies,
of the Royal Artillery, well known as a most accurate observer of
nature and an indefatigable collector of her treasures, as well as a
most admirable painter of them, once informed me, that when abroad,
having taken up this animal and placed it upon his hand, it gave him
a considerable shock, as if from an electric jar, with its legs,
which he felt as high as his shoulders; and, dropping the creature,
he observed six marks upon his hand where the six feet had stood.
You may now possibly think that I have nearly gone through the
catalogue of our _personal_ assailants of the insect tribes. If such,
however, is your expectation, I fear you will be disappointed, since
I have many more, and some tremendous ones, to enumerate: but as a
small compensation for such a detail of evils and injuries to which
our species is exposed from foes seemingly so insignificant, and of
acts of rebellion of the vilest and most despised of our subjects
against our boasted supremacy, the objects to which I shall next call
your attention are not, like most of our apterous enemies, calculated
to excite disgust and nausea when we see them or speak of them; nor
do they usually steal upon us during the silent hours of repose,
(though I must except here the gnat or mosquito,) but are many of
them very beautiful, and boldly make their attack upon us in open
day, when we are best able to defend ourselves. Borne on rapid wings,
wherever they find us, they endeavour to lay us under contribution,
and the tribute they exact is our blood. Wonderful and various are
the weapons that enable them to enforce their demand. What would
you think of any large animal that should come to attack you with a
tremendous apparatus of knives and lancets issuing from its mouth?
Yet such are the instruments by means of which the fire-eyed and
blood-thirsty horse-fly (_Tabanus_, L.) makes an incision in your
flesh; and then, forming a siphon of them, often carries off many
drops of your blood[162]. The pain they inflict, when they open a
vein, is usually very acute. A fly of this kind not only occasioned
Mr. Sheppard considerable pain by its bite, but also produced
swelling and blackness round one eye; and the flesh of his cheek and
chin was so enlarged from it as to hang down. And Mr. W. S. MacLeay
thus describes to me the annoyance he suffered from one of them. "I
went down the other day to the country, and was fairly driven out of
it by the _Hæmatopota pluvialis_, which attacked me with such fury,
that although I did not at last venture beyond the door without a
veil, my face and hands were swelled to that degree as to be scarcely
yet recovered from the effects of their venom. I was obliged on my
return to town to stay two days at home. Whenever this insect bites
me it has this effect, and I have never been able to discover any
remedy for the torture it puts me to." In this country, however,
the attacks of these flies are usually not frequent enough to make
them more than a minor "misery of human life;" but the burning-fly
(_brulot_) or sand-fly of America[163] and the West Indies,
which seem to be the same insect, causes a much more intolerable
anguish, which has been compared to what a red-hot needle or a
spark of fire would occasion us to endure. Lambert, in his _Travels
through Canada_, &c. says, "They are so very small as to be hardly
perceptible in their attacks; and your forehead will be streaming
with blood before you are sensible of being amongst them[164]."--Yet
we have one species (_Stomoxys calcitrans_) alluded to in a former
letter as so nearly resembling the common house-fly[165], which,
though its oral instruments are to appearance not near so tremendous,
is a much greater torment than the horse-fly. This little pest, I
speak feelingly, incessantly interrupts our studies and comfort in
showery weather, making us even stamp like the cattle by its attacks
on our legs; and, if we drive it away ever so often, returning
again and again to the charge. In Canada they are infinitely worse.
"I have sat down to write," says Lambert, (who though he calls it
the house-fly is evidently speaking of the Stomoxys,) "and have been
obliged to throw away my pen in consequence of their irritating bite,
which has obliged me every moment to raise my hand to my eyes, nose,
mouth, and ears in constant succession. When I could no longer write,
I began to read, and was always obliged to keep one hand constantly
on the move towards my head. Sometimes in the course of a few minutes
I would take half a dozen of my tormentors from my lips, between
which I caught them just as they perched[166]."
The swallow-fly (_Craterina Hirundinis_[167]), whose natural food is
the bird after which it is named, has been known to make its repast
on the human species. One found its way into a bed of the Rev. R.
Sheppard, where it first, for several nights, sorely annoyed a friend
of his, and afterwards himself, without their suspecting the culprit.
After a close search, however, it was discovered in the form of this
fly, which, forsaking the nest of the swallow, had by some chance
taken its station between the sheets, and thus glutted itself with
the blood of man.--In travelling between Edam and Purmerend in North
Holland (July 21, 1815), in an open vehicle, I was much teased by
another bird-fly (_Ornithomyia avicularia_) (two individuals of which
I caught) alighting upon my head, and inserting its rostrum into my
flesh.--Mr. Sheppard remarks, as a reason for this dereliction of
their appropriate food, that no sooner does life depart from the
bird that these flies infest, than they immediately desert it and
take flight, alighting upon the first living creature that they meet
with; which if it be not a bird they soon quit, but, as it should
seem from the above facts, not before they have made a trial how it
will suit them as food.
But of all the insect-tormentors of man, none are so loudly and
universally complained of as the species of the genus _Culex_, L.,
whether known by the name of gnats or mosquitos[168]. Pliny, after
Aristotle, distinguishes well between _Hymenoptera_ and _Diptera_,
when he says the former have their sting in their tail, and the
latter in their mouth; and that to the one this weapon is given as
the instrument of vengeance, and to the other of avidity[169]. But
the instrument of avidity in the genus of which I am speaking, is
even more terrible than that of vengeance in most insects that are
armed with it: like the latter also, as appears from the consequent
inflammation and tumour, it instills into its wound a poison; the
principal use of which, however, is to render the blood more fluid
and fitter for suction. This weapon, which is more complex than the
sting of hymenopterous insects, consisting of five pieces besides
the exterior sheath, some of which seem simply lancets, while others
are barbed like the spicula of a bee's sting, is at once calculated
for piercing the flesh and forming a siphon adapted to imbibe the
blood[170]. There are several species of this genus whose bite
is severe, but none is to be compared to the common gnat (_Culex
pipiens_, L.), if, as has been generally affirmed, it be synonymous
with the mosquito (though perhaps several species are confounded
under both names); and to this, the most insatiable of blood-suckers,
I shall principally direct your attention[171].
In this country they are justly regarded as no trifling evil; for
they follow us to all our haunts, intrude into our most secret
retirements, assail us in the city and in the country, in our
houses and in our fields, in the sun and in the shade: nay, they
pursue us to our pillows, and either keep us awake by the ceaseless
hum of their droning pipe, and their incessant endeavours to fix
themselves upon our face, or some uncovered part of our body; or, if
in spite of them we fall asleep, awaken us by the acute pain which
attends the insertion of their oral stings; attacking with most
avidity the softer sex, and trying their temper by disfiguring their
beauty. But although with us they are usually rather teasing than
injurious; yet upon some occasions they have approached nearer to
the character of a plague, and emulated with success the mosquitos
of other climates. Thus, we are told that in the year 1736 they were
so numerous, that vast columns of them were seen to rise in the air
from Salisbury cathedral, which at a distance resembled columns of
smoke, and occasioned many people to think that the cathedral was on
fire. A similar occurrence, in like manner giving rise to an alarm
of the church being on fire, took place in July 1812 at Sagan in
Silesia[172]. In the following year at Norwich, in May, at about six
o'clock in the evening, the inhabitants of that city were alarmed by
the appearance of smoke issuing from the upper window of the spire of
the cathedral, for which at the time no satisfactory account could
be given, but which was most probably produced by the same cause.
And in the year 1766, in the month of August, they appeared in such
incredible numbers at Oxford as to resemble a black cloud, darkening
the air and almost totally intercepting the beams of the sun. One
day, a little before sun-set, six columns of them were observed to
ascend from the boughs of an apple-tree, some in a perpendicular and
others in an oblique direction, to the height of fifty or sixty feet.
Their bite was so envenomed, that it was attended by violent and
alarming inflammation; and one when killed usually contained as much
blood as would cover three or four square inches of wall[173]. Our
great poet Spenser seems to have witnessed a similar appearance of
them, which furnished him with the following beautiful simile:
As when a swarme of gnats at eventide
Out of the fennes of Allan doe arise,
Their murmuring small trumpets sownden wide,
Whiles in the air their clust'ring army flies,
That as a cloud doth seem to dim the skies;
Ne man nor beast may rest or take repast
For their sharp wounds and noyous injuries.
Till the fierce northern wind with blust'ring blast
Doth blow them quite away, and in the ocean cast.
In Marshland in Norfolk, as I learn from a lady who had an
opportunity of personal inspection, the inhabitants are so annoyed
by the gnats, that the better sort of them, as in many hot climates,
have recourse to a gauze covering for their beds, to keep them
off during the night. Whether this practice obtains in other fen
districts I do not know.