Harvesting Ants and Trap-Door Spiders

Abstract

THIS beautifully illustrated little book is a good example of what can be done by a careful observer in a very short time. It might have been thought that the habits of European insects were pretty well known, and that a person comparatively new to the subject could not hope to add much to our knowledge. But the fact is quite otherwise, for Mr. Moggridge, in the course of a few winters spent in the south of Europe has, by careful observation, thrown considerable light on the habits and economy of two important groups of insects, and, as regards one of them, has disproved the dogmatic assertions of several eminent entomologists. Nothing is more curious than the pertinacity with which scientific men will often draw general conclusions from their own special observations, and then use these conclusions to set aside the observations of other men. Mr. Moggridge now confirms, in many of their minutest details, the accounts given by classical writers of the habits of ants. These habits were recorded with so much appearance of minute observation, that they bear the impress of accuracy; yet because the Ants of England and of Central Europe have different habits, it was concluded that the old authors invented all these details, and that they were at once accepted as truths and became embodied in the familiar sayings of the time. The ants were described as ascending the stalks of cereals and gnawing off the grains, while others below detached the seed from the chaff and carried it home; as gnawing off the radicle to prevent germination, and spreading their stores in the sun to dry after wet weather. Latreille, Huber, Kirby, Blanchard, and many less eminent authors, treat these statements with contempt, and give reasons why they cannot be true for European species, yet we here find them verified in every detail by observations at Mentone and other places on the shores of the Mediterranean. Mr. Moggridge has, however, supplemented these observations by discovering the granaries in which they are stored (sometimes excavated in solid rock), of which accurate plans are given. He has seen them in the act of collecting seeds, and has traced seeds to the granaries, from which all husks and refuse are carefully carried away; he has seen them bring out the grains to dry after rain, and nibble off the radicle from those which were germinating; lastly, he has seen them (in confinement) feed on the seeds so collected. Avery curious point is, that the collections of seeds, although stored in very damp situations, very rarely germinate; yet nothing has been done to deprive them of vitality, for on being sown they grow vigorously. The species of harvesting ants observed were, Pheidole megacephala, Atta structor, A. barbara, and a larger and differently coloured variety of the last. Atta structor is found over a large part of Central Europe, yet, as it has never been observed to lay up stores of seeds in more northern countries, it either has different habits according to locality, or local observers have strangely overlooked its peculiarities. The seeds of more than thirty species of plants were found stored up, none of which were cereals; but at Hyeres, M. Germain St. Pierre has observed these latter stored by ants in such quantities that he thinks their depredations must cause serious loss to cultivators. Thus we have another important confirmation of the statements of the old writers. Harvesting Ants and Trap-Door Spiders. Notes and Observations on their Habits and Dwellings. By J. Traherne Moggridge. (L. Reeve and Co., 1873.)