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 bursting of 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 shell, so thin that it may be punched through with the point of the finger: and even kyanized wood, unless impregnated with an extra quantity 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 assaults.
They do not appear in the hills above the elevation of 2000 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.
HYMENOPTERA. Mason Wasp.—In Ceylon as in all other countries, the order of hymenopterous insects arrests us less by the beauty of their forms than the marvels of their sagacity and the achievements of their instinct. A fossorial wasp of the family of Sphegidoe,[1] which is distinguished by its metallic lustre, enters by the open windows, and disarms irritation at its movements by admiration of the graceful industry with which it stops up the keyholes and similar apertures with clay in order to build in them a cell, into which it thrusts the pupa of some other insect, within whose body it has previously introduced its own eggs; and, enclosing the whole with moistened earth, the young parasite, after undergoing its transformations, gnaws its way into light, and emerges a four-winged fly.[2]
1: It belongs to the genus Pelopoeus, P. Spinoloe, St. Fargeau. The Ampulex compressa, which drags about the larvæ of cockroaches into which it has implanted its eggs, belongs to the same family.
2: Mr. E. L. Layard has given an interesting account of this Mason wasp in the Annals and Magazine of Nat. History for May, 1853.
"I have frequently," he says, "selected one of these flies for observation, and have seen their labours extend over a period of a fortnight or twenty days; sometimes only half a cell was completed in a day, at others as much as two. I never saw more than twenty cells in one nest, seldom indeed that number, and whence the caterpillars were procured was always to me a mystery. I have seen thirty or forty brought in of a species which I knew to be very rare in the perfect state, and which I had sought for in vain, although I knew on what plant they fed.
"Then again how are they disabled by the wasp, and yet not injured so as to cause their immediate death? Die they all do, at least all that I have ever tried to rear, after taking them from the nest.
"The perfected fly never effects its egress from the closed aperture, through which the caterpillars were inserted, and when cells are placed end to end, as they are in many instances, the outward end of each is always selected. I cannot detect any difference in the thickness in the crust of the cell to cause this uniformity of practice. It is often as much as half an inch through, of great hardness, and as far as I can see impervious to air and light. How then does the enclosed fly always select the right end, and with what secretion is it supplied to decompose this mortar?"