Supplement to Harvesting Ants and Trap-Door Spiders

by John Traherne Moggridge; Octavius Pickard-Cambridge

[146] In the United States, and indeed in the New World generally, it seems to be the custom to call all the larger "ground spiders," and especially the trap-door spiders, Tarantulas, but these, in fact, form a distinct group by themselves, belonging to the family Lycosidæ.

I first made the acquaintance of Lycosa narbonensis near the glass-works west of Cannes, where this spider may not rarely be found living in tubular burrows in sandy clearings among the pine woods along the shore (Pinus pinea, the stone pine).

I have already (Ants and Spiders, p. 146), alluded to an account given by M. Léon Dufour of his observations on the nest and habits of the true tarantula (Lycosa tarentula), which he discovered in Spain.

The nests of L. narbonensis at Cannes resembled those described by M. Dufour, but the cylindrical, subterranean burrows were apparently shorter. It was extremely difficult to trace their course, on account of the loose sand which poured into the tubes and choked them up, and I only succeeded in doing so completely in one case, when I stuffed the tube with cotton-wool before proceeding to dig. Here the open tube, which was quite simple, and about 1 inch in diameter, descended vertically for 3¹/₄ inches, and was then suddenly bent so as to become horizontal, terminating shortly afterwards in a triangular chamber, the floor of which measured 2 inches across at the widest part, and was strewed with the remains of beetles and other insects.

The nest was lined throughout with coarse silk, which had a blackish hue, owing to the presence of the filaments of what I believe to have been some undeveloped fungoid growth. The mouth of the tube was open, and frequently surmounted by a short tubular prolongation, commencing at the surface of the ground, which formed a sort of chimney about an inch high and from an inch to an inch and a quarter across; this was composed of fibres of plants, pine-needles, and especially of a large branching lichen, very common in the neighbourhood of the nests, and all these materials were woven together and kept in place by a few threads of silk spun here and there.

It was not every nest that was furnished with a chimney, nor were all the chimneys equally complete, for in some cases they consisted merely of a small rim or one-sided lip, while in others they resembled little birds' nests, and were sufficiently firm and compact to permit of my carrying them away. It appeared to me that these chimneys served as screens to prevent the loose sand from being swept into the burrows by the winds which rage over that open seashore plain, and that they were more or less complete in proportion as the exposure was greater or less, and the sand looser or more bound together.

I captured eight of these spiders, and here, as in the trap-door group, the female alone inhabited the nest.

Besides this habit, they have other points in common with trap-door spiders; such, for example, as the resemblance which exists between this nest and that of Theraphosa Blondii from Brazil (see p. 188, above), and between the chimney of this Tarantula and the aërial prolongation of the tube sometimes found in nests of the wafer type.

But perhaps the most suggestive point of resemblance consists in the habit which this Tarantula possesses of covering and closing the aperture of the nest during the winter with a thin layer of materials, similar to those of which the chimney is composed, and, like them, bound together with silk. This is, in fact, an immovable wafer-door, and precisely resembles those which I have seen constructed by Nemesia Manderstjernæ, and N. Eleanora, when captive and placed in an artificial hole in the earth.

The tubes are, as has been already stated, open during the spring, and we may suppose that the spider, on the approach of warm weather, wakes up from her winter lethargy, and tears away this concealing thatch. But if one of these spiders should by chance happen to free this silk-woven thatch by cutting round some three-fourths of its circumference, so as to leave it still attached to the rim of the aperture of the nest by the remaining quarter, she would then have made for herself a veritable, though rather rude trap-door of the wafer kind.