our property from the inclemency and injuries of the atmosphere,
are of consequence to us: yet these, solid and substantial as they
appear, are not secure from the attack of insects; and even our
furniture often suffers from them. A great part of our comfort
within doors depends upon our apartments being kept clean and neat.
Spiders by their webs, which they suspend in every angle, and flies
by their excrements, which they scatter indiscriminately upon every
thing, interfere with this comfort, and add much to the business
of our servants. Even ants will sometimes plant their colonies
in our kitchens, (I have known the horse-ant, _Formica rufa_, do
this,) and are not easily expelled. Those of Sierra Leone, as I was
once informed by the learned Professor Afzelius, make their way
by millions through the houses. They resolutely pursue a straight
course; and neither buildings nor rivers, even though myriads
perish in the attempt, can divert them from it. Numerous are the
tribes of insects that seek their food in our timber, whether laid
up in store for our future use, employed in our houses, buildings,
gates or fences, or made up into furniture. The several species
of Mr. Marsham's genus _Ips_ (which includes the coleopterous
genera _Apate_, _Bostrichus_, _Hylessinus_, _Hylurgus_, _Tomicus_,
_Platypus_, _Scolytus_, and _Phloiotribus_ of modern systematists)
all prey upon timber, feeding between the bark and the wood, and many
of them excavating curious pinnated labyrinths. Almost every kind of
tree has a species of this genus appropriated to it, and some have
more than one[428]. The Stag-beetle tribe, or _Lucanidæ_, and several
of the weevils[429], have a similar appetite, but penetrate deeper
into the wood. The most extensive family, however, of timber-borers
are the capricorn beetles, including the Fabrician genera of
_Prionus_, _Cerambyx_, _Lamia_[430], _Stenocorus_, _Calopus_,
_Rhagium_, _Gnoma_, _Saperda_, _Callidium_, and _Clytus_. The larva
of these, as soon as hatched, leaves its first station between the
bark and wood, and begins to make its way into the solid timber,
(some of them plunging even into the iron heart of the oak, and one
even perforating lead[431],) where it eats for itself tortuous
paths, at its first starting perhaps not bigger than a pin's head,
but gradually increasing in dimensions as the animal increases in
magnitude, till it attains in some instances to a diameter of one or
two inches. Only conceive what havoc the grub of the vast _Prionus
giganteus_ must make in a beam! Percival is probably speaking of this
beetle, when, in his account of Ceylon, he tells us, "There is an
insect found here which resembles an immense over-grown beetle. It
is called by us a carpenter, from its boring large holes in timber,
of a regular form, and to the depth of several feet, in which, when
finished, it takes up its habitation[432]." Seeing the perfect insect
come out of these holes, an unentomological observer would naturally
conclude that the beetle he saw had formed it, and lived in it; but,
doubtless, the whole was the work of the grub[433].--Of all the
coleopterous genera there is none the species of which are generally
so rich, resplendent and beautiful as those of _Buprestis_: these
likewise, in their first state, there is abundant reason to believe,
derive their nutriment from the produce of the forest, in which they
sometimes remain for many years before they assume their perfect
state, and appear in their full splendour, as if nature required
more time than usual to decorate these lovely insects. We learn from
Mr. Marsham, that the grub of _B. splendida_ was ascertained to have
existed in the wood of a deal table more than twenty years[434].--In
this enumeration of timber-eating beetles, I must not forget the
Fabrician genera, _Anobium_ and _Ptilinus_, because of one of them
(_Anobium pertinax_) Linné complains "_terebravit et destruxit
sedilia mea_[435];" and I can renew the same complaint against
_A. striatum_, which not only has destroyed my chairs, but also
picture-frames, and has perforated in every direction the deal floor
of my chamber, from which it annually emerges through little round
apertures in great numbers.--The utility of entomological knowledge
in economics was strikingly exemplified, when the great naturalist
just mentioned, at the desire of the king of Sweden, traced out the
cause of the destruction of the oak-timber in the royal dock-yards;
and, having detected the lurking culprit under the form of a beetle,
(_Lymexylon navale_) by directing the timber to be immersed during
the time of the metamorphosis of that insect and its season of
oviposition, furnished a remedy which effectually secured it from
its future attacks[436].--No coleopterous insects are more singular
than those that belong to the genus _Pausus_, L.; and one of them at
least, remarkable for emitting a phosphoric light from the globes of
its antennæ, is also a timber-feeder[437].--Amongst the _Hymenoptera_
there are many insects that injure us in this department. The species
of the genus _Sirex_, probably all of them in their _larva_ state,
have no appetite but for ligneous food. Linné has observed this
with respect to _S. Spectrum_ and _Camelus_; and Mr. Marsham, on
the authority of Sir Joseph Banks, relates that several specimens
of _S. Gigas_ were seen to come out of the floor of a nursery in a
gentleman's house, to the no small alarm and discomfiture of both
nurse and children[438].--The genus _Trypoxylon_, many species
of _Crabro_, _Eumenes Parietum_, Latreille's genera _Xylocopa_,
_Chelostoma_, _Heriades_, _Megachile_ and _Anthophora_, (all
separated from _Apis_, L.,) perforate posts and rails and other
timber, to form cells for their young[439].
The Linnean order _Aptera_ furnishes another timber-eating insect,
a kind of wood-louse, though scarcely an eighth of the size of the
common one, (_Limnoria terebrans_ of Dr. Leach,) which in point of
rapidity of execution seems to surpass all its European brethren, and
in many cases may be productive of more serious injury than any of
them, since it attacks the wood-work of piers and jetties constructed
in salt-water, and so effectually, as to threaten the rapid
destruction of those in which it has established itself. In December
1815 I was favoured by Charles Lutwidge, esq. of Hull, with specimens
of wood from the piers at Bridlington Quay which wofully confirm the
fears entertained of their total ruin by the hosts of these pygmy
assailants that have made good a lodgement in them, and which, though
not so big as a grain of rice, ply their masticatory organs with such
assiduity as to have reduced great part of the wood-work into a state
resembling honey-comb. One specimen was a portion of a three-inch
fir plank nailed to the North Pier about three years since, which
is now crumbled away to less than an inch in thickness--in fact,
deducting the space occupied by the cells which cover both surfaces
as closely as possible, barely half an inch of solid wood is left;
and though its progress is slower in oak, that wood is equally liable
to be attacked by it.--If this insect were easily introduced to new
stations, it might soon prove as destructive to our jetties as the
_Teredo navalis_ to those of Holland, and induce the necessity of
substituting stone for wood universally, whatever the expense: but
happily it seems endowed with very limited powers of migration;
for, though it has spread along both the South and East Piers of
Bridlington harbour, it has not yet, as Mr. Lutwidge informs me,
reached the dolphin nor an insulated jetty within the harbour.--No
other remedy against its attacks is known than that of keeping the
wood free from salt-water for three or four days, in which case it
dies; but this method it is obvious can be rarely applicable[440].
How dear are their books, their cabinets of the various productions
of nature, and their collections of prints and other works of art and
science, to the learned, the scientific, and the virtuosi! Even these
precious treasures have their insect enemies. The larva of _Aglossa
pinguinalis_, whose ravages in another quarter I have noticed
before[441], will establish itself upon the binding of a book, and
spinning a robe, which it covers with its own excrement[442], will
do it no little injury. A mite (_Cheyletus eruditus_) eats the paste
that fastens the paper over the edges of the binding, and so loosens
it[443]. I have also often observed the caterpillar of another little
moth, of which I have not ascertained the species, that takes its
station in damp old books, between the leaves, and there commits
great ravages; and many a black-letter rarity, which in these days
of Bibliomania would have been valued at its weight in gold, has
been snatched by these destroyers from the hands of book-collectors.
The little wood-boring beetles before mentioned (_Anobium pertinax_
and _striatum_) also attack books, and will even bore through
several volumes. M. Peignot mentions an instance where, in a public
library but little frequented, _twenty-seven_ folio volumes were
perforated in a straight line by the same insect, (probably one of
these species,) in such a manner that on passing a cord through the
perfectly round hole made by it, these twenty-seven volumes could be
raised at once[444]. The animals last mentioned also destroy prints
and drawings, whether framed, or preserved in a porte-feuille. Our
collections of quadrupeds, birds, insects and plants have likewise
several terrible insect enemies, which without pity or remorse often
destroy or mutilate our most highly prized specimens. _Ptinus Fur_
and _Anthrenus Musæorum_, two minute beetles, are amongst the worst,
especially the latter, whose singular gliding larva, when once it
gets amongst them, makes astonishing havoc, the birds soon shedding
their feathers, and the insects falling to pieces. Mr. W. S. MacLeay
informs me that at the Havana it is exceedingly difficult to preserve
insects, &c., as the _ants_ devour every thing.--One of the worst
plagues of the entomologist is a mite (_Acarus Destructor_, Schrank):
this, if his specimens be at all damp, eats up all the muscular
parts, (_Cantharis vesicatoria_ being almost the only insect that is
not to its taste,) and thus entirely destroys them.--If spiders by
any means get amongst them, they will do no little mischief.--Some
I have observed to be devoured by a minute moth, perhaps _Tinea
Insectella_; and in the posterior thighs of a species of _Locusta_
from China, I once found, one in each thigh, a small beetle
congenerous with _Antherophagus pallens_, that had devoured the
interior. It is, I believe, either _Acarus Destructor_ or _Cheyletus
eruditus_ that eats the gum employed to fasten down dried plants.
There are other insects which do not confine themselves to one or two
articles, but make a general and indiscriminate attack upon our dead
stock. Ulloa mentions one peculiar to Carthagena, called there the
_comegen_, which he describes as a kind of moth or maggot so minute
as to be scarcely visible to the naked eye[445]. This destroys, says
he, the furniture of houses, particularly all kinds of hangings,
whether of cloth, linen, or silk, gold or silver stuffs or lace; in
short, every thing except solid metal. It will in a single night ruin
all the goods of a warehouse in which it has got footing, reducing
bales of merchandize to dust without altering their appearance, so
that the mischief is not perceived till they come to be handled[446].
If we make some deduction from this account for exaggeration, still
the amount of damage will be very considerable.
There are three kinds of insects better known, to whose ravages, as
most prominent and celebrated, I shall last call your attention.
The insects I mean are the cock-roach (_Blatta orientalis_), the
house-cricket (_Gryllus domesticus_), and the various species of
white ants (_Termes_). The last of these, most fortunately for us,
are not yet naturalized.
The cock-roaches hate the light, at least the kind that is most
abundant in Britain, (for _B. germanica_, which abounds in some
houses, is bolder, making its appearance in the day, and running
up the walls and over the tables, to the great annoyance of the
inhabitants,) and never come forth from their hiding-places till the
lights are removed or extinguished. In the London houses, especially
on the ground-floor, they are most abundant, and consume every thing
they can find, flour, bread, meat, clothes, and even shoes[447]. As
soon as light, natural or artificial, re-appears, they all scamper
off as fast as they can, and vanish in an instant. These pests are
not indigenous here, and perhaps no where in Europe, but are one of
the evils which commerce has imported: and we may think ourselves
well off that others of the larger species of the genus have not been
introduced in the same way--as, for instance, _Blatta gigantea_,
a native of Asia, Africa, and America, many times the size of the
common one,--which, not content with devouring meat, clothes and
books, even attacks persons in their sleep, and the extremities of
the dead and dying[448].
The house-cricket may perhaps be deemed a still more annoying insect
than the common cock-roach, adding an incessant noise to its ravages;
since, although, for a short time, it may not be unpleasant to hear
"the cricket chirrup in the hearth,"
so constant a din every evening must very much interrupt comfort
and conversation. These garrulous animals, which live in a kind of
artificial torrid zone, are very thirsty souls, and are frequently
found drowned in pans of water, milk, broth, and the like. Whatever
is moist, even stockings or linen hung out to dry, is to them a
_bonne bouche_; they will eat the scummings of pots, yeast, crumbs of
bread, and even salt, or any thing within their reach. Sometimes they
are so abundant in houses as to become absolute pests, flying into
the candles and into people's faces.
At Cuddapa, in the ceded districts to the northward of Mysore,
Captain Green was much annoyed by a jumping insect, which from his
description I should take for the larva of a species of cricket. They
were of a dun colour, and from half to three-fourths of an inch in
length. They abounded at night, and were very injurious to papers
and books, which they both discoloured and devoured; leather also
was eaten by them. Such was their boldness and avidity, that they
attacked the exposed parts of the body when you were asleep, nibbling
the ends of the fingers, particularly the skin under the nails, which
was only discoverable by a slight soreness that succeeded. So great
was their agility that they could seldom be caught or crushed. They
were a mute insect, but probably the imago would make noise enough.
But the _white ants_, wherever they prevail, are a still worse plague
than either of these insects--they are the great calamity, as Linné
terms them, of both the Indies. When they find their way into houses
or warehouses, nothing less hard than metal or glass escapes their
ravages. Their favourite food, however, is wood of all kinds, except
the teak (_Tectona grandis_) and iron-wood (_Sideroxylon_), which are
the only sorts known that they will not touch[449]; and so infinite
are the multitudes of the assailants, and such is the excellence of
their tools, that all the timber-work of a spacious apartment is
often destroyed by them in a few nights. Exteriorly, however, every
thing appears as if untouched; for these wary depredators, and this
is what constitutes the greatest singularity of their history, carry
on all their operations by sap and mine, destroying first the inside
of solid substances, and scarcely ever attacking their outside, until
first they have concealed it and their operations with a coat of
clay. A general similarity runs through the proceedings of the whole
tribe; but the large African species, (called by Smeathman _Termes
bellicosus_,) _T. fatalis_ is the most formidable. These insects
live in large clay nests, from whence they excavate tunnels all
round, often to the extent of several hundred feet; from these they
will descend a considerable depth below the foundation of a house,
and rise again through the floors; or, boring through the posts and
supports of the building, enter the roof, and construct there their
galleries in various directions. If a post be a convenient path to
the roof, or has any weight to support, which how they discover is
not easily conjectured, they will fill it with their mortar, leaving
only a trackway for themselves; and thus, as it were, convert it from
wood into stone as hard as many kinds of free-stone. In this manner
they soon destroy houses, and sometimes even whole villages when
deserted by their inhabitants, so that in two or three years not a
vestige of them will remain.
These insidious insects are not less expeditious in destroying the
wainscoting, shelves, and other fixtures of a house than the house
itself. With the most consummate art and skill they eat away all the
inside of what they attack, except a few fibres here and there which
exactly suffice to keep the two sides, or top and bottom, connected,
so as to retain the appearance of solidity after the reality is gone;
and all the while they carefully avoid perforating the surface,
unless a book or any other thing that tempts them should be standing
upon it. Kæmpfer, speaking of the white ants of Japan, gives a
remarkable instance of the rapidity with which these miners proceed.
Upon rising one morning he observed that one of their galleries of
the thickness of his little finger had been formed across his table;
and, upon a further examination, he found that they had bored a
passage of that thickness up one foot of the table, formed a gallery
across it, and then pierced down another foot into the floor: all
this was done in the few hours that intervened between his retiring
to rest and his rising[450]. They make their way also with the
greatest ease into trunks and boxes, even though made of mahogany,
and destroy papers and every thing they contain, constructing their
galleries and sometimes taking up their abode in them. Hence, as
Humboldt informs us, throughout all the warmer parts of equinoctial
America, where these and other destructive insects abound, it
is infinitely rare to find papers which go fifty or sixty years
back[451]. In one night they will devour all the boots and shoes that
are left in their way; cloth, linen, or books are equally to their
taste; but they will not eat cotton, as Captain Green informs me.
I myself have to deplore that they entirely consumed a collection
of insects made for me by a friend in India, more especially as it
sickened him of the employment. In a word, scarcely any thing, as I
said before, but metal or stone comes amiss to them. Mr. Smeathman
relates, that a party of them once took a fancy to a pipe of fine old
Madeira, not for the sake of the wine, almost the whole of which they
let out, but of the staves, which however I suppose were strongly
imbued with it, and perhaps on that account were not less to the
taste of our epicure Termites. Having left a compound microscope in
a warehouse at Tobago for a few months, on his return he found that
a colony of a small species of white ant had established themselves
in it, and had devoured most of the wood-work, leaving little
besides the metal and glasses[452]. A shorter period sufficed for
their demolition of some of Mr. Forbes's furniture. On surveying a
room which had been locked up during an absence of a few weeks, he
observed a number of advanced works in various directions towards
some prints and drawings in English frames; the glasses appeared
to be uncommonly dull, and the frames covered with dust. "On
attempting," says he, "to wipe it off, I was astonished to find the
glasses fixed to the wall, not suspended in frames as I left them,
but completely surrounded by an incrustation cemented by the white
ants, who had actually eaten up the deal frames and back-boards, and
the greater part of the paper, and left the glasses upheld by the
incrustation, or covered way, which they had formed during their
depredation[453]." It is even asserted that the superb residence of
the Governor-General at Calcutta, which cost the East India Company
such immense sums, is now rapidly going to decay in consequence
of the attacks of these insects[454].--But not content with the
dominions they have acquired, and the cities they have laid low on
Terra Firma, encouraged by success the white ants have also aimed at
the sovereignty of the ocean, and once had the hardihood to attack
even a British ship of the line; and, in spite of the efforts of her
commander and his valiant crew, having boarded they got possession of
her, and handled her so roughly, that when brought into port, being
no longer fit for service, she was obliged to be broken up[455].
And here, I think, I see you throw aside my papers, and hear you
exclaim--"Will this enumeration of scourges, plagues, and torments
never be finished? Was the whole insect race created merely with
punitive views, and to mar the fair face of universal nature?
Are they all, as our Saviour said figuratively of one genus, the
scorpion, the powerful agents and instruments of the great enemy
of mankind[456]?" If you view the subject in another light, you
will soon, my friend, be convinced that, instead of this, insects
generally answer the most beneficial ends, and promote in various
ways, and in an extraordinary degree, the welfare of man and animals;
and that the series of evils I have been engaged in enumerating
mostly occur partially, and where they exceed their natural limits;
God permitting this occasionally to take place, not merely with
punitive views, but also to show us what mighty effects he can
produce by instruments seemingly the most insignificant: thus calling
upon us to glorify his power, wisdom, and goodness, so evidently
manifested whether he relaxes or draws tight the reins by which
he guides insects in their course, and regulates their progress;
and more particularly to acknowledge his overruling Providence
so conspicuously exhibited by his measuring them, as it were, and
weighing them, and telling them out, so that, their numbers, forces
and powers being annually proportioned to the work he has prescribed
to them, they may neither exceed his purpose nor fall short of it.
From the picture I have drawn, and I assure you it is not
overcharged, you will be disposed to admit, however, the empire of
insects over the works of creation, and to own that our prosperity,
comfort and happiness are intimately connected with them; and
consequently that the knowledge and study of them may be extremely
useful and necessary to promote these desirable ends, since the
knowledge of the cause of any evil is always a principal, if not an
indispensable, step towards a remedy.
I shall now bid adieu to this unpromising subject, which has so long
occupied my pen, and I fear wearied your attention, and in my next
bring before you a more agreeable scene, in which you will behold the
_benefits_ we receive by the ministry of insects.
I am, &c.
FOOTNOTES:
[405] _Amœn. Acad._ iii. 345.
[406] Sparrman, i. 103. This insect, by Swedish entomologists, is
supposed to be a species of _Anobium_, F., (_Ptinus_, L.,) but the
specimen preserved in the Linnean cabinet is _Silpha rosea_ of Mr.
Marsham (_Cacidula pectoralis_, Meg.). A small beetle of the first
family of _Cryptophagus_ of Major Gyllenhal swarms often in the ship
biscuit, and may probably be the insect Sparrman here complains of
under the name of _Dermestes paniceus_.
[407] See above, p. 172.
[408] De Geer, v. 46. This insect appears nearly related to Mr.
Marsham's _Corticaria pulla_ (_E. B._ i. 11. 14. _Latridius
porcatus_, Herbst), if it be not the same insect.
[409] _Amœn. Acad._ iii. 345.
[410] This name has long been given to this insect, and the
Characters of the genus were drawn by Mr. Curtis before the
publication of Meigen's fifth volume (in which the genus is called
_Piophila_); it is therefore retained. See Curtis _Brit. Ent. t._ 126.
[411] Reaum. iii. 276.
[412] Leeuwenh. _Epist._ 99.
[413] _Ceylon_, 307.
[414] _Voyage_, &c. 72.
[415] Williamson's _East India Vade Mecum_.
[416] _Calcutta, a Poem_, 85.
[417] _Ptinus piceus_, Marsh.
[418] On examining ninety-two chests of _opium_, part of the
cargo saved from the Charlton, previously to reshipping them from
Chittagong for China, thirteen were found to be full of white ants,
which had almost wholly devoured the opium. _Article from Chittagong,
Nov._ 1812, _in one of the Newspapers, July_ 31, 1813.
[419] _Ptinus rubellus_, Marsh.
[420] _Bibl. Nat._ i. 125. b. 126. a.
[421] Sir Geo. Staunton's _Voy._ 8vo. 189.
[422] Kerr in _Philos. Trans._ 1781.
[423] Reaum. iii. 266.
[424] Ibid. 59.
[425] Reaum. iii. 42.
[426] Ibid. 257.
[427] _Amœn. Acad._ iii. 346.
[428] Kirby in _Linn. Trans._ v. 250.
[429] _Curculio lignarius_, Marsh. _Rhinosimus ruficollis_, Latr.
[430] The species of the genus _Dorcadion_ separated from _Lamia_ are
discovered to live upon the roots of grass.
[431] The _larva_ of a _Callidium_ (which Dr. Leach has discovered
to be _C. Bajulus_) sometimes does material injury to the wood-work
of the roofs of houses in London, piercing in every direction the
fir-rafters, and, when arrived at the perfect state, making its way
out even through sheets of lead one-sixth of an inch thick, when they
happen to have been nailed upon the rafter in which it has assumed its
final metamorphosis. I am indebted to the kindness of Sir Joseph Banks
for a specimen of such a sheet of lead, which, though only eight inches
long and four broad, is thus pierced with twelve oval holes, of some of
which the longest diameter is a quarter of an inch! Mr. Charles Miller
first discovered lead in the stomach of the larva of this insect.
[432] P. 310.
[433] See Kirby, _ubi supr._ 253.--More than a hundred species of the
Capricorn tribe, many of them nondescripts, were collected in the
neighbourhood of Rio de Janeiro by Captain Hancock, of the Foudroyant.
[434] In _Linn. Trans._ x. 399.
[435] _Syst. Nat._ 565. 2.
[436] Smith's _Introduction to Botany_, Pref. xv.
[437] Afzelius in _Linn. Trans._ iv. 261.
[438] _Linn. Trans._ x. 403.
[439] Kirby, _Mon. Ap. Ang._ i. 152-194. Latreille, _Gen._ iv. 161--.
[440] In order to ascertain how far _pure_ sea water is essential
to this insect, and consequently what danger exists of its being
introduced into the woodwork of our docks and piers communicating with
our salt-water rivers, as at Hull, Liverpool, Bristol, Ipswich, &c.,
where it might be far more injurious than even on the coast, I have,
since December 15th 1815, when Mr. Lutwidge was so kind as to furnish
me with a piece of oak full of the insects in a living state, poured
a not very strong solution of common salt over the wood, every other
day, so as to keep the insects constantly wet. On examining it this day
(Feb. 5th 1816) I found them alive; and, what seems to prove them in
as good health as in their natural habitat, numbers have established
themselves in a piece of fir-wood which I nailed to the oak, and have
in this short interval, and in winter too, bored many cells in it.
[441] See p. 226.
[442] Reaum. iii. 270.
[443] Schrank _Enum. Ins. Austr._ 513. 1058.
[444] Horne's _Introd. to Bibliography_, i. 311.
[445] It appears from Humboldt (_Personal Narrative_, E. T. v. 116.)
that the destructive insects called by this name, are _Termites_.
[446] Ulloa, i. 67.
[447] _Amœn. Acad._ iii. 345.
[448] Drury's _Insects_, iii. Preface.
[449] It is not its hardness that protects the teak, as the Asiatic
Termites attack Lignum Vitæ, but probably some essential oil
disagreeable to them with which it is impregnated. This is the
more likely, since they will eat it when it is old and has been
long exposed to the air. _Tannin_ has been conjectured to be the
protecting substance, but erroneously, as leather of every kind is
devoured by them. Williamson's _East India Vade Mecum_, ii. 56. It is
its hardness probably that protects the iron-wood from the African
Termites. Smeathman in _Philos. Trans._ 1781. 11. 47.
[450] _Japan_, ii. 127.
[451] _Political Essay on New Spain_, iv. 135.