[164] i. 127. The West India sand-fly was noticed by the late Robinson
Kittoe, Esq., who however did not recollect their fetching blood.
[165] See above, p. 48-49.
[166] _Travels_, &c. i. 126.
[167] See Curtis' _Brit. Ent._ t. 122.
[168] It has been generally supposed by naturalists, that the
Mosquitos of America belong to the Linnean genus _Culex_; but the
celebrated traveller Humboldt asserts that the term _Mosquito_,
signifying a _little fly_, is applied there to a _Simulium_, Latr.
(_Simulia_, Meig.), and that the _Culices_, which are equally
numerous and annoying, are called _Zancudoes_, which means _long
legs_. The former, he says, are what the French call _Moustiques_,
and the latter _Maringouins_. _Personal Narrative_, E. T. v. 93.
[169] Plin. _Hist. Nat._ l. xi. c. 28. Aristot. _Hist. Animal._ l. i.
c. 5.
[170] Pliny was aware of this double office of the proboscis of a
gnat, and has well described it. "Telum vero perfodiendo tergori
quo spiculavit ingenio? Atque ut in capaci, cum cerni non possit
exilitas, ita reciproca geminavit arte, ut _fodiendo_ acuminatum
pariter _sorbendoque_ fistulosum esset." _Hist. Nat._ l. xi. c. 2.
[171] Humboldt has described several South American species.
_Personal Narrative_, v. 97. note *. Engl. Tr.
[172] Germar's _Magazin der Entomologie_, i. 137.
[173] _Philos. Trans._ 1767, 111-13. I once witnessed a similar
appearance at Maidstone in Kent.
[174] Weld's _Travels_, 8vo. edit. 205. Yet Mouffet affirms the same:
"Morsu crudeles et venenati, triplices caligas, imo _ocreas_, item
perforantes." 81.
[175] Acerbi's _Travels_, ii. 5. 34-5. 51. Linn. _Flor. Lapp._ 380-1.
_Lach. Lapp._ ii. 108. De Geer, vi. 303-4.
[176] Reaum. iv. 573.
[177] Dr. Clarke's _Travels_, i. 388.
[178] Jackson's _Marocco_, 57.
[179] _Travels_, ii. 93. Mr. W. S. MacLeay, in a letter I recently
received from him, observes, speaking of his residence at the Havana;
"The disagreeables are ants, scorpions, mygales, and mosquitos. The
latter were quite a pest on my first arrival within the tropics; but
now I mind them about as much as I did _gnats_ in England."
[180] Humboldt's _Personal Narrative_, E. T. v. 87-. Most writers
by the term mosquitos mean gnats; and for them it is here chiefly
employed, but may be regarded as including both plagues.
[181] Theodorit. _Hist. Eccl._ 1. ii. c. 30.
[182] Mouffet, 85. Amoreux, 119.
[183] Viz. _Mosquito_ Bay in St. Christopher's; _Mosquitos_, a town
in the Island of Cuba; and the _Mosquito_ country in North America.
[184] Mouffet, 85.
[185] Deut. vii. 20. Josh. xxiv. 12.
[186] Amoreux, 242.
[187] _Philos. Trans._ i. 201.
[188] Hawkesworth's _Cook_, iii. 223.
[189] Stedman, ii. 94.
[190] Bingley, iii. 385, first edit.
[191] Knox's _Ceylon_, 24.
[192] Stedman, ii. 142.
[193] Ulloa's _Voy._ i. 61, 62. Dr. Clarke's _Travels_, i. 486.
Amoreux, 197. Mr. W. S. MacLeay relates to me that soon after his
arrival at the Havana he was stung by an immense scorpion, but was
agreeably surprised to find the pain considerably less than the sting
of a wasp, and of incomparably shorter duration.
[194] Andrews's _Anecdotes_, 427. See on the subject of Scorpions
Amoreux, 41-54. 176-205.
[195] Fab. _Suppl._ 294. 2.
[196] _Catal. Ham._ 1797. 151-195.
[197] PLATE VII. FIG. 13. _a"_.
[198] Ulloa's _Voyage_, i. 61.
[199] Amoreux, 217-226. See also 67-70.
[200] p. 31.
[201] Jackson's _Marocco_, second edit.
[202] Ulloa, i. 64. Probably the _Cafafi_, a white fly noticed by
Humboldt, is synonymous with this of Ulloa, which could only be
prevented from creeping between the threads of the curtains by
keeping them wet. _Personal Narrative_, E. T. v. 107.
[203] _Lach. Lapp._ i. 208, 209. _Fl. Lapp._ 382, 383. It appears
however, from other authors, that they do bite.
[204] Young's _Travels in France_, i. 298. These flies are equally
troublesome and tormenting in Sweden. See _Amœn. Acad._ iii. 343.
[205] Cowhage has been administered with success as an
_anthelminthic_, as has likewise spun glass pounded; the spicula of
these substances destroying the worms. The hair of the caterpillars
here alluded to, and perhaps also of the larva of _Euprepia Caja_,
(the Tiger-Moth,) might probably be equally efficacious.
[206] Reaum. ii. 191-5.
[207] Mouffet, 185. Plin. _Hist. Nat._ l. xxxviii. c. 9. Amoreux, 158.
[208] Amoreux, 210-212.
[209] Ulloa's Voyage, b. vi. c. 3. Hamilton (_Travels in Colombia_,
as quoted in the Literary Gazette, April 28, 1827.) also mentions a
spider called the _Caya_, rather large, found in the broken ground
and among the rocks, from the body of which a poison so active is
emitted, that men and mules have died in an hour or two after the
venomous moisture had fallen on them. This is evidently the same
insect with that mentioned by Ulloa, and confirms the above account
of its venomous effects.
[210] Waterton (_Wanderings in S. America_, 53.) gives the recipe
by which the Macousho Indians prepare the poison, in which they dip
their arrows. It consists of a vine called the Wourali, which is the
principal ingredient; the roots and stalks of some other plants;
two species of ants, the sting of one of which is so venomous that
it produces a fever; a quantity of the strongest Indian pepper
(_Capsicum_), and the pounded fangs of two kinds of serpents.
[211] Tulpius, _Obs. Med._ l. ii. c. 51. t. 7. f. 3. _Edinb. Med. and
Surg. Journ._ n. 35. 42-48. Derham, _Physic. Theol._ 378. note _b._
Lowthorp, _Philos. Trans._ iii. 135.
[212] _Philos. Trans._ 1665. x. 391. Shaw's _Abridg._ ii. 224.
[213] Mead, _Med. Sacr._ 105.
[214] _London Medical Review_, v. 340.
[215] _Philos. Trans._ ubi supra.
[216] Fulvius Angelinus et Vincentius Alsarius _De verme admirando
per nares egresso_. Ravennæ 1610.
[217] Azara, 217. I cannot help suspecting this to be synonymous with
the _Œstrus Hominis_ next mentioned.
[218] From Pallas _N. Nord. Beytr._ i. 157.
[219] _Essai sur la Géograph. des Plantes_, 136.
[220] Clark in _Linn. Trans._ iii. 323, note.
[221] Leeuw. _Epist._ Oct. 17, 1687.
[222] _Edinb. Med. and Surg. Journ._ ubi supra. De Geer, vi. 26, 27.
[223] 216.
[224] Lempriere _On the Diseases of the Army in Jamaica_, ii. 182.
[225] In passing through this parish last spring, I inquired of the
mail-coachman whether he had heard of this story; and he said the
fact was well known.
[226] _Philos. Mag._ ix. 366.
[227] Bonnet, v. 144.
[228] _Mém. Apterolog._ 79.
[229] _Universal History_, iv. 70. Ed. 1779.
[230] Wisd. xvii. 12.
LETTER V.
_INJURIES CAUSED BY INSECTS._
INDIRECT INJURIES.
Having detailed to you the _direct_ injuries which we suffer from
insects, I am now to call your attention to their _indirect_ attacks
upon us, or the injury which they do our property; and under this
view also you will own, with the fullest conviction, that they
are not beings that can with prudence or safety be disregarded or
despised. Our property, at least that part exposed to the annoyance
of these creatures, may be regarded as consisting of animal and
vegetable productions, and that in two states; when they are living,
namely, and after they are dead. I shall therefore endeavour to
give you a sketch of the mischief which they occasion, first to our
_living animal_ property, then to our _living vegetable_ property;
and lastly to our _dead stock_, whether animal or vegetable.
Next to our own persons, the _animals_ which we employ in our
business or pleasures, or fatten for food, individually considered,
are the most valuable part of our possessions--and at certain
seasons, hosts of insects of various kinds are incessant in their
assaults upon most of them.--To begin with that noble animal the
_horse_.--See him, when turned out to his pasture, unable to touch
a morsel of the food he has earned by his labours. He flies to the
shade, evidently in great uneasiness, where he stands continually
stamping from the pain produced by the insertion of the weapons
sheathed in the proboscis of a little fly (_Stomoxys calcitrans_)
before noticed as attacking ourselves[231]. This alights upon him
sometimes in one place and sometimes in another, and never lets
him rest while the day lasts.--See him again when in harness and
travelling. He is bathed in blood flowing from innumerable wounds
made by the knives and lancets of various horse-flies (_Tabanus_,
L.), which assail him as he goes, and allow him no respite[232];
and consider that even this is nothing to what he suffers in other
climates from the same pest. In North America, vast clouds of
different species--so abundant as to obscure every distant object,
and so severe in their bite as to merit the appellation of burning
flies--cover and torment the horses to such a degree as to excite
compassion even in the hearts of the pack-horsemen. Some of them are
nearly as big as humble-bees; and, when they pierce the skin and
veins of the unhappy beast, make so large an orifice that, besides
what they suck, the blood flows down its neck, sides, and shoulders
in large drops like tears, till, to use Bartram's expression, "they
are all in a gore of blood." Both the dog-tick and the American tick
before mentioned, especially the latter, also infest the horse. Kalm
affirms, that he has seen the under parts of the belly, and other
places of the body, so covered by them, that he could not introduce
the point of a knife between them. They were deeply buried in the
flesh; and in one instance that he witnessed, the miserable creature
was so exhausted by continual suction, that it fell, and afterwards
died in great agonies[233].
No quadruped is more infested by the gad-fly, sometimes also
improperly called the breese[234], than the horse. In this country
no fewer than three species attack it. The most common sort, known
by the name of the horse-bee (_Gasterophilus Equi_), deposits its
eggs (which being covered with a slimy substance adhere to the hairs)
on such parts of the body as the animal can reach with its tongue;
and thus, unconscious of what it is doing, it unwarily introduces
into its own citadel the troops of its enemy.--Another species (_G.
hæmorrhoidalis_) is still more troublesome to it, ovipositing upon
the lips; and in its endeavours to effect this, from the excessive
titillation it occasions, giving the poor beast the most distressing
uneasiness. At the sight of this fly horses are always much agitated,
tossing their heads about in the air to drive it away; and, if this
does not answer, galloping off to a distant part of their pasture,
and, as their last resource, taking refuge in the water, where the
gad-flies never follow them. We learn from Reaumur, that in France
the grooms, when they observe any bots (which is the vulgar name for
the larvæ and pupæ of these flies) about the anus of a horse or in
its dung, thrust their hand into the passage to search for more; but
this seems a useless precaution, which must occasion the animal great
pain to answer no good end: for when the bots are passing through
the body, having ceased feeding, they can do no further injury. In
Sweden, as De Geer informs us, they act much more sensibly: those
that have the care of horses are accustomed to clean their mouths
and throats with a particular kind of brush, by which method they
free them from these disagreeable inmates before they have got into
the stomach, or can be at all prejudicial to them[235].
Providence has doubtless created these animals to answer some
beneficial purpose; and Mr. Clark's judicious conjectures are an
index which points to the very kind of good our cattle may derive
from them, as acting the part of perpetual stimuli or blisters: yet
when they exceed certain limits, as is often the case with similar
animals employed for purposes equally beneficial, they become
certainly the causes of disease, and sometimes of death.
How troublesome and teasing is that cloud of flies (_Anthomyia
meteorica_) which you must often have noticed in your summer rides,
hovering round the head and neck of your horse, accompanying him as he
goes, and causing a perpetual tossing of the former[236]!--And still
more annoying in Lapland, as we learn from Linné[237], is the furious
assault of the minute horse-gnat, (_Culex equinus_, L.) which infests
these beasts in infinite numbers, running under the mane and amongst
the hair, and piercing the skin to suck their blood.--An insect of the
same genus is related to attack them in a particular district in India
in so tremendous a manner as to cause incurable cancers, which finally
destroy them[238].--But of all the insect tormentors of these useful
creatures, there is none more trying to them than the forest-fly
(_Hippobosca equina_). Attaching themselves to the parts least covered
with hair, particularly under the belly between the hind legs, they
irritate the quietest horse, and make him kick so as often to hazard
the safety of his rider or driver. This singular animal runs sideways
or backwards like a crab; and, being furnished with an unusual number
of claws, it adheres so firmly that it is not easy to take it off;
and even if you succeed in this, its substance is so hard, that by
the utmost pressure of your finger and thumb it is difficult to kill
it; and if you let it go with life, it will immediately return to the
charge.--Amongst the insect plagues of horses, I should also have
enumerated the larva of _Lixus paraplecticus_, which Linné considers
as the cause of the equine disease, called in Sweden, after the
_Phellandrium aquaticum_, "_Stâkra_," had not the observations of the
accurate De Geer rendered it doubtful whether the insect be at all
connected with this malady[239].
Another quadruped contributing greatly to our domestic comfort, from
which we derive a considerable portion of our animal food, and which,
on account of its patient and laborious character when employed in
agriculture, is an excellent substitute for the horse, (you will
directly perceive I am speaking of the _ox_, whether male or female,)
is also not exempt from insect domination. At certain seasons the whole
terrified herd, with their tails in the air, or turned upon their
backs, or stiffly stretched out in the direction of the spine, gallop
about their pastures, making the country re-echo with their lowings,
and finding no rest till they get into the water. Their appearance and
motions are at this time so grotesque, clumsy, and seemingly unnatural,
that we are tempted rather to laugh at the poor beasts than to pity
them, though evidently in a situation of great terror and distress. The
cause of all this agitation and restlessness is a small gad-fly (_Œ.
Bovis_), less than the horse-bee, the object of which, though it be not
to bite them, but merely to oviposit in their hides, is not put into
execution without giving them considerable pain.
When oxen are employed in agriculture, the attack of this fly is
often attended with great danger, since they then become perfectly
unmanageable; and, whether in harness or yoked to the plough, will
run directly forward. At the season when the Œstrus infests them,
close attention should be paid, and their harness so constructed that
they may easily be let loose.
Reaumur has minutely described the ovipositor, or singular organ by
which these insects are enabled to bore a round hole in the skin of
the animal and deposit their eggs in the wound. The anus of the female
is furnished with a tube of a corneous substance, consisting of four
pieces, which, like the pieces of a telescope, are retractile within
each other. The last of these terminates in five points, three of which
are longer than the others, and hooked: when united together they form
an instrument very much like an auger or gimlet; only, having these
points, it can bite with more effect[240]. He thinks the infliction
of the wound is not attended by much pain, except where very sensible
nerves are injured, when the animal, appearing to be seized with a
kind of phrensy, begins to gambol, and run with such swiftness that
nothing can stop it. From this semblance of temporary madness in oxen
when pursued and bored by the Œstrus, the Greeks applied the term
to any sudden fit of fury or violent impulse in the human species,
calling such ebullitions an _Œstrus_. The female fly is observed to
be very expeditious in oviposition, not more than a few seconds; and
while she is performing the operation, the animal attempts to lash her
off, as it does other flies, with its tail. The circular hole, made
by the auger just described, always continues open, and increases in
diameter as the larva increases in size; thus enabling it to receive a
sufficient supply of air by means of its anal respiratory plates, which
are usually near the orifice.--But though these insects thus torment
and terrify our cattle, they do them no material injury. Indeed they
occasion considerable tumours under the skin, where the bots reside,
varying in number from three or four to thirty or forty; but these seem
unattended by any pain, and are so far from being injurious, that they
are rather regarded as proofs of the goodness of the animal, since
these flies only attack young and healthy subjects. The tanners also
prefer those hides that have the greatest number of bot-holes in them,
which are always the best and strongest[241].
The Stomoxys, and several of the other flies before enumerated, as
well as the dog and American ticks, are as prejudicial to the ox as
to the horse. One species of Hippobosca I have reason to believe is
appropriated to them; yet, since a single specimen only has hitherto
been taken[242], little can be said with respect to it.--A worse
pest than any hitherto enumerated, is a minute fly, concerning the
genus of which there is some doubt, Fabricius considering it as a
Rhagio, (_R. columbaschensis_,) and Latreille as a Simulium[243]; but
to whatever genus it may belong, it is certainly a most destructive
little creature. In Servia and the Bannat it attacks the cattle in
infinite numbers, penetrates, according to Fabricius, their generative
organs, but according to other accounts their nose and ears, and by its
poisonous bite destroys them in the short space of four or five hours.
Much injury was sustained in 1813 from this insect in the palatinate
of Arad in Hungary and in the Bannat; in Banlack not fewer than two
hundred horned cattle perishing from its attacks, and in Versetz, five
hundred. It appears towards the latter end of April or beginning of May
in such indescribable swarms as to resemble clouds, proceeding as some
think from the region of Mehadia, but according to others from Turkey.
Its approach is the signal for universal alarm. The cattle fly from
their pastures; and the herdsman hastens to shut up his cows in the
house, or, when at a distance from home, to kindle fires, the smoke of
which is found to drive off this terrible assailant. Of this the cattle
are sensible, and as soon as attacked run towards the smoke, and are
generally preserved by it[244].
Tabani in this country do not seem to annoy our oxen so much as they
do our horses: perhaps for this immunity they may be indebted to
the thickness of their hides; but Virgil's beautiful description of
the annoyance that the Grecian Œstrus, called by the Romans Asilus,
belongs evidently to one of the _Tabanidæ_. As the passage has not
been very correctly translated, I shall turn poet on the occasion,
and attempt to give it you in a new dress.
Through waving groves where Selo's torrent flows,
And where, Alborno, thy green Ilex grows,
Myriads of insects flutter in the gloom,
(Œstrus in Greece, Asilus named at Rome,)
Fierce and of cruel hum. By the dire sound
Driven from the woods and shady glens around
The universal herds in terror fly;
Their lowings shake the woods and shake the sky,
And Negro's arid shore----
In some parts of Africa also insects of this tribe do incredible
mischief. What would you think, should you be told that one species
of fly drives both inhabitants and their cattle from a whole
district? Yet the terrible _Tsaltsalya_ or _Zimb_ of Bruce (and the
world seems now disposed to give more credit to the accounts of that
traveller) has power to produce such an effect. This fly, which is
a native of Abyssinia, both from its habits and the figure, appears
to belong to the _Tabanidæ_, and perhaps is congenerous with the
_Œstrus_ of the Greeks[245].
Small as this insect is, we must acknowledge the elephant,
rhinoceros, lion and tiger vastly his inferior. The appearance,
nay the very sound of it occasions more trepidation, movements and
disorder both in the human and brute creation, than whole herds of
the most ferocious wild beasts in tenfold greater numbers than they
ever are would produce. As soon as this plague appears, and their
buzzing is heard, all the cattle forsake their food, and run wildly
about the plain till they die worn out with fatigue, fright, and
hunger. No remedy remains for the residents on such spots but to
leave the black earth and hasten down to the sands of Atbara, and
there they remain while the rains last. Camels, and even elephants
and rhinoceroses, though the two last coat themselves with an armour
of mud, are attacked by this winged assassin and afflicted with
numerous tumours. All the inhabitants of the sea-coast of Melinda
down to Cape Gardefui, to Saba and the south of the Red Sea, are
obliged in the beginning of the rainy season to remove to the next
sand to prevent all their stock of cattle from being destroyed. This
is no partial emigration--the inhabitants of all the countries from
the mountains of Abyssinia northward, to the confluence of the Nile
and Astaboras, are once a year obliged to change their abode and seek
protection in the sands of Beja; nor is there any alternative or
means of avoiding this, though a hostile band were in the way capable
of spoiling them of half their substance[246]. This fly is truly a
Beelzebub[247]: and perhaps it was this, or some species related to
it, that was the prototype of the Philistine idol worshiped under
that name and in the form of a fly.
I must not conclude this subject of insects hurtful to our cattle,
without noticing a beetle much talked of by the ancients for its
mischievous properties in this respect. You will soon and rightly
conjecture that I am speaking of the Buprestis[248], so called from
the injury which it has been supposed to occasion to oxen or kine.
Modern writers have been much divided in their opinion to what genus
this celebrated insect belongs. All indeed have regarded it as of the
_Coleoptera_ order; but here their agreement ceases. Linné should
seem to have looked upon it as a species of the genus to which he has
given its name; but these, being timber insects, are not very likely
to be swallowed by cattle with their food. Geoffroy thinks it to be a
_Carabus_ or _Cicindela_, but with as little reason, since the species
of these genera do not feed amongst the herbage; and though they are
sometimes found running there, yet their motions are so rapid, that it
is not very likely that cattle would often swallow them while feeding.
M. Latreille, in an ingenious essay on this insect[249], suspects
it to belong to the genus _Melöe_, and as this feeds upon herbs,
(_M. Proscarabæus_ and _M. violaceus_, upon the Ranunculi, so widely
disseminated in our pastures,) his opinion seems to rest upon more
solid grounds than that of his predecessors; but yet I think the insect
in question rather belongs to _Mylabris_, and for the following reason.