Part 46 (1/2)
[Footnote 1: Phyllium siccifolium.]
[Ill.u.s.tration: STICK INSECT AND MANTIS]
It rests on its abdomen, the legs serving to drag it slowly along, and thus the flatness of its att.i.tude serves still further to add to the appearance of a leaf. One of the most marvellous incidents connected with its organisation was exhibited by one which I kept under a gla.s.s shade on my table, it laid a quant.i.ty of eggs, that, in colour and shape, were not to be distinguished from _seeds_. They were brown, and pentangular, with a short stem, and slightly punctured at the intersections.
[Ill.u.s.tration]
The ”soothsayer,” on the other hand (_Mantis superst.i.tiosa._ Fab.[1]), little justifies by its propensities the appearance of gentleness, and the att.i.tudes of sanct.i.ty, which have obtained for it the t.i.tle of the ”praying mantis.” Its habits are carnivorous, and degenerate into cannibalism, as it preys on the weaker individuals of its own species.
Two which I enclosed in a box were both found dead a few hours after, literally severed limb from limb in their encounter. The formation of the foreleg enables the tibia to be so closed on the sharp edge of the thigh as to amputate any slender substance grasped within it.
[Footnote 1: _M. aridifolia_ and _M. extensicollis_, as well as _Empusa gongylodes_, remarkable for the long leaf-like head, and dilatations on the posterior thighs, are common in the island.]
_The Stick-insect_.--The _Phasmidae_ or spectres, another cla.s.s of orthoptera, present as close a resemblance to small branches or leafless twigs as their congeners do to green leaves. The wing-covers, where they exist, instead of being expanded, are applied so closely to the body as to detract nothing from its rounded form, and hence the name which they have acquired of ”_walking-sticks_.” Like the _Phyllium_, the _Phasma_ lives exclusively on vegetables, and some attain the length of several inches.
Of all the other tribes of the _Orthoptera_ Ceylon possesses many representatives; in swarms of c.o.c.kroaches, gra.s.shoppers, locusts, and crickets.
NEUROPTERA. _Dragon-flies_.--Of the _Neuroptera_, some of the dragon-flies are pre-eminently beautiful; one species, with rich brown-coloured spots upon its gauzy wings, is to be seen near every pool.[1] Another[2], which dances above the mountain streams in Oovah, and amongst the hills descending towards Kandy, gleams in the sun as if each of its green enamelled wings had been sliced from an emerald.
[Footnote 1: _Libellula pulch.e.l.la_.]
[Footnote 2: _Euphaea splendens_.]
_The Ant-Lion._--Of the ant-lion, whose larvae have earned a bad renown from their predaceous ingenuity, Ceylon has, at least, four species, which seem peculiar to the island.[1] This singular creature, preparatory to its pupal transformation, contrives to excavate a conical pitfall in the dust to the depth of about an inch, in the bottom of which it conceals itself, exposing only its open mandibles above the surface; and here every ant and soft-bodied insect which curiosity tempts to descend, or accident may precipitate into the trap, is ruthlessly seized and devoured by its ambushed inhabitant.
[Footnote 1: _Palpares contrarius_, Walker; _Myrmeleon gravis_, Walker; _M. dirus_, Walker; _M. barbarus_, Walker.]
_The White Ant_.--But of the insects of this order the most noted are the _white ants_ or termites (which are ants only by a misnomer). They are, unfortunately, at once ubiquitous and innumerable in every spot where the climate is not too chilly, or the soil too sandy, for them to construct their domed edifices.
These they raise from a considerable depth under ground, excavating the clay with their mandibles, and moistening it with tenacious saliva[1]
until it a.s.sume the appearance, and almost the consistency, of sandstone. So delicate is the trituration to which they subject this material, that the goldsmiths of Ceylon employ the powdered clay of the ant hills in preference to all other substances in the preparation of crucibles and moulds for their finer castings: and KNOX says, ”the people use this finer clay to make their earthen G.o.ds of, it is so pure and fine.”[2] These structures the termites erect with such perseverance and durability that they frequently rise to the height of ten or twelve feet from the ground, with a corresponding diameter. They are so firm in their texture that the weight of a horse makes no apparent indentation on their solidity; and even the intense rains of the monsoon, which no cement or mortar can long resist, fail to penetrate the surface or substance of an ant hill.[3] In their earlier stages the termites proceed with such energetic rapidity, that I have seen a pinnacle of moist clay, six inches in height and twice as large in diameter, constructed underneath a table between sitting down to dinner and the removal of the cloth.
[Footnote 1: It becomes an interesting question whence the termites derive the large supplies of moisture with which they not only temper the clay for the construction of their long covered ways above ground, but for keeping their pa.s.sages uniformly damp and cool below the surface. Yet their habits in this particular are unvarying, in the seasons of droughts as well as after rain; in the driest and least promising positions, in situations inaccessible to drainage from above, and cut off by rocks and impervious strata from springs from below. Dr.
Livingstone, struck with this phenomenon in Southern Africa, asks: ”Can the white ants possess the power of combining the oxygen and hydrogen of their vegetable food by vital force so as to form water?”--_Travels_, p.
22. And he describes at Angola, an insect[A] resembling the _Aphrophora spumaria_; seven or eight individuals of which distil several pints of water every night.--P. 414. It is highly probable that the termites are endowed with some such faculty: nor is it more remarkable that an insect should combine the gases of its food to produce water, than that a fish should decompose water in order to provide itself with gas. FOURCROIX found the contents of the air-bladder in a carp to be pure nitrogen.--_Yarrell_, vol. i. p. 42. And the aquatic larva of the dragon-fly extracts air for its respiration from the water in which it is submerged. A similar mystery pervades the inquiry whence plants under peculiar circ.u.mstances derive the water essential to vegetation.]
[Footnote A: _A. goudotti?_ Bennett.]
[Footnote 2: KNOX'S _Ceylon_, Part i, ch. vi, p.24.]
[Footnote 3: Dr. HOOKER, in his _Himalayan Journal_ (vol. i. p. 20) is of opinion that the nests of the termites are not independent structures, but that their nucleus is ”the debris of clumps of bamboos or the trunks of large trees which these insects have destroyed.” He supposes that the dead tree falls leaving the stump coated with sand, _which the action of the weather soon fas.h.i.+ons into a cone_. But independently of the fact that the ”action of the weather” produces little or no effect on the closely cemented clay of the white ants'
nest, they may be daily seen constructing their edifices in the very form of a cone, which they ever after retain. Besides which, they appear in the midst of terraces and fields where no trees are to be seen: and Dr. Hooker seems to overlook the fact that the termites rarely attack a living tree; and although their nests may be built against one, it continues to flourish not the less for their presence.]
As these lofty mounds of earth have all been carried up from beneath the surface, a cave of corresponding dimensions is necessarily scooped out below, and here, under the mult.i.tude of miniature cupolas and pinnacles which canopy it above, the termites hollow out the royal chamber for their queen, with s.p.a.cious nurseries surrounding it on all sides; and all are connected by arched galleries, long pa.s.sages, and doorways of the most intricate and elaborate construction. In the centre and underneath the s.p.a.cious dome is the recess for the queen--a hideous creature, with the head and thorax of an ordinary termite, but a body swollen to a hundred times its usual and proportionate bulk, and presenting the appearance of a ma.s.s of shapeless pulp. From this great progenitrix proceed the myriads that people the subterranean hive, consisting, like the communities of the genuine ants, of labourers and soldiers, which are destined never to acquire a fuller development than that of larvae, and the perfect insects which in due time become invested with wings and take their departing flight from the cave. But their new equipment seems only destined to facilitate their dispersion from the parent nest, which takes place at dusk; and almost as quickly as they leave it they divest themselves of their ineffectual wings, waving them impatiently and twisting them in every direction till they become detached and drop off, and the swarm, within a few hours of their emanc.i.p.ation, become a prey to the night-jars and bats, which are instantly attracted to them as they issue in a cloud from the ground. I am not prepared to say that the other insectivorous birds would not gladly make a meal of the termites, but, seeing that in Ceylon their numbers are chiefly kept in check by the crepuscular birds, it is observable, at least as a coincidence, that the dispersion of the swarm generally takes place at _twilight_. Those that escape the _caprimulgi_ fall a prey to the crows, on the morning succeeding their flight.
The strange peculiarity of the omnivorous ravages of the white ants is that they shrink from the light; in all their expeditions for providing food they construct a covered pathway of moistened clay, and their galleries above ground extend to an incredible distance from the central nest. No timber, except ebony and ironwood, which are too hard, and those which are strongly impregnated with camphor or aromatic oils, which they dislike, presents any obstacle to their ingress. I have had a case of wine filled, in the course of two days, with almost solid clay, and only discovered the presence of the white ants by the escape from the corks. I have had a portmanteau in my tent so peopled with them in the course of a single night that the contents were found worthless in the morning. In an incredibly short time a detachment of these pests will destroy a press full of records, reducing the paper to fragments; and a shelf of books will be tunnelled into a gallery if it happen to be in their line of march. The timbers of a house when fairly attacked are eaten from within till the beams are reduced to an absolute sh.e.l.l, so thin that it may be punched through with the point of the finger: and even kyanized wood, unless impregnated with an extra quant.i.ty of corrosive sublimate, appears to occasion them no inconvenience. The only effectual precaution for the protection of furniture is incessant vigilance--the constant watching of every article, and its daily removal from place to place, in order to baffle their a.s.saults.
They do not appear in the hills above the elevation of 4000 or 5000 feet. One species of white ant, the _Termes Taprobanes_, was at one time believed by Mr. Walker to be peculiar to the island, but it has recently been found in Sumatra and Borneo, and in some parts of Hindustan.
There is a species of Termes in Ceylon (_T. monoceros_), which always builds its nest in the hollow of an old tree; and, unlike the others, carries on its labours without the secrecy and protection of a covered way. A marching column of these creatures may be observed at early morning in the vicinity of their nest, returning laden with the spoils collected during their foraging excursions. These consist of comminuted vegetable matter, derived, it may be, from a thatched roof, if one happens to be within reach, or from the decaying leaves of a coco-nut.
Each little worker in the column carries its tiny load in its jaws; and the number of individuals in one of these lines of march must be immense, for the column is generally about two inches in width, and very densely crowded. One was measured which had most likely been in motion for hours, moving in the direction of the nest, and was found to be upwards of sixty paces in length. If attention be directed to the ma.s.s in motion, it will be observed that flanking it on each side throughout its whole length are stationed a number of horned soldier termites, whose duty it is to protect the labourers, and to give notice of any danger threatening them. This latter duty they perform by a peculiar quivering motion of the whole body, which is rapidly communicated from one to the other for a considerable distance: a portion of the column is then thrown into confusion for a short time, but confidence soon returns, and the progress of the little creatures goes on with steadiness and order as before. The nest is of a black colour, and resembles a ma.s.s of scoriae; the insects themselves are of a pitchy brown.[1]