This fur-moth is perhaps the best known species in our houses; it is a small yellowish-grey insect with pale brown spots on the wings. This is, I believe, the species of which I have secured the larvæ. Fur and feathers are alike its staple diet, and it is easily distinguished from other kinds by a dark brown mark on the second segment of the grub, which mark I can discern by a magnifying glass.
The linings of chairs and sofas and the stuffing of carriage cushions, horse-hair pillows, &c., are constantly attacked by Tinea biselliella, while cloth, flannel, and any woollen material, suits the taste of the almost universal Tinea tapetzella, against whose ravages every housekeeper has to devise a variety of protective plans. The moth is so small it can creep through minute crevices—a knot-hole at the back of a drawer or a keyhole will afford it access to the winter garments which have been put away in supposed security.[[7]] Tapetzella differs in appearance from the fur moth as its wings are half black and half grey, and it is also of larger size. In laying her eggs the moth has the foresight to place them rather widely apart, so that each grub may find space enough in which to feed; it is this habit which renders the creature specially destructive, as it attacks many parts of a garment and does not confine its ravages to one spot. The larva of this species forms covered galleries in which it works, mining its way along the surface of the material, and eating off the pile wherever it goes and leaving threadbare tracks behind it.
Pellionella adopts a different method. The first work of the minute grub on issuing from the egg is to form a round case in which it may live, for it does not eat unless it has a house of its own. This curious habit may be seen in many other species amongst the Tineæ. I have already mentioned one which forms its house of wheat grains; another chooses particles of stone of which it constructs its dwelling, and then feeds on the lichens which grow upon old walls. Out of the fluffy seeds of the willow one Tinea forms a sort of muff in which it lives. Other species of the group form little tents upon the leaves of the elm, oak, and many kinds of fruit-trees, these cases being so minute as to be unobserved unless the insect is moving within. One of the most remarkable of all the species is one which inhabits the leaves of the nettle. The tent looks like a tiny hedgehog, as it is formed of minute portions of the leaf glued together and studded all over with the stinging hairs of the nettle.
Mr. James Rennie in his “Insect Architecture” gives such an excellent description of the weaving operations of the Pellionella grub that I cannot do better than quote his observations upon it: “It selected a single hair for the foundation of its intended structure; this it cut very near the skin in order, we suppose, to have as long as possible, and placed it in a line with its body. It then immediately cut another, and placing it parallel to the first, bound both together with a thread of its own silk. The same process was repeated with other hairs till the little creature had made a fabric of some thickness, and this it went on to extend till it was large enough to cover its body, which (as is usual with caterpillars) it employed as a model and measure for regulating its operations. The chamber was ultimately finished by a fine and closely woven tapestry of silk. When the caterpillar increases in length it takes care to add to the length of its house by working in fresh hairs at either end; and if it be shifted to furs or feathers of different colours it may be made to construct a parti-coloured tissue like a Scotch plaid. But the grub increases in thickness as well as in length, so that its first house becoming too narrow, it must either enlarge it or build a new one. It prefers enlarging the premises, and sets to work precisely as we should do, slitting the case on the two opposite sides and then adroitly inserting between them two pieces of the requisite size. When the structure is finished, the insect deems itself secure to feed upon the fur within its reach, provided it is dry and free from grease, which the grub will not touch.”
This account shows that the moth-grub can secrete a kind of silk with which it lines its cell, but it can use other materials out of which to weave a house for itself. When that house becomes too small it knows how to put in two side-pieces to make it fit the size of its body. When full grown, this same case forms its temporary coffin, for the little creature simply closes up the entrance and hangs itself up in some convenient place until in due time it comes out a perfect moth, ready to lay its eggs and pursue the instincts of its race. Surely we must admit that these lives which are carried on in our houses are very curious and worth investigation. When we think of the minute size of these grubs (scarcely a quarter of an inch in length) and the vigour of the instinct they display, the secret mode in which they work in airless drawers and boxes, the perseverance with which the moth finds entrance into these hiding-places, we must credit this small insect with many remarkable qualities. Its lineage is extremely ancient, for it is twice mentioned in the oldest book in the Bible, and it is not a little remarkable that Job seems to have been accurately acquainted with the habits of the Tinea larvæ, since he says, in speaking of an ungodly man, “He buildeth his house as a moth, and as a booth that the keeper maketh” (Job xxvii. 18).
Both of these images point to the temporary nature of the dwelling. A booth consists of a few branches put together at the top of a pole where a man can sit and scare away wild animals from the Eastern fields of fruit and grain—an erection easily removed in a few moments; it is appropriately likened to the moth grub’s tiny case which is cast aside after a few weeks or months, when the perfect insect has emerged. There are seven or eight allusions in the Scriptures to the ravages of the moth in destroying apparel, and remembering that Eastern people are in the habit of hoarding immense stores of richly embroidered clothing as an evidence of great wealth, there can be no doubt but that the many species of Tinea which are found in Palestine were a very real danger to be guarded against with the utmost solicitude.
THE DEATH-WATCH.
“Alas! the poor gentleman will never get from hence,” said the Landlady to me, “for I heard the Death-Watch all night long.”—Sterne.
THE DEATH-WATCH.