Page:Hardwicke's Science-Gossip - Volume 1.pdf/177

produce but little this year, thanks to the caterpillars. This is attributed to the fact that the peasants suffer their children to destroy the nests of the small birds, which are the only instruments that can effectually protect trees from caterpillars. It is calculated that there were formerly 10,000 birds' nests in every square league of cultivated land in France. Each nest is supposed to contain on an average four young ones, which the old birds fed with 60 caterpillars a day. The old birds fed with 60 caterpillars a day. The old birds were supposed to eat 60; making 120 caterpillars a day altogether. This multiplied by 10,000 nests will give 1,200,000 caterpillars destroyed every day in a square league of a well-planted country. The peasants one would suppose would have sufficient common sense to protect the birds which render them such valuable service, but they appear utterly ignorant on the subject. The only bird respected by the peasants, and especially the Norman peasant, is the wren, and that from a superstitious motive.—Gardener's Chronicle.

Pugnacity of Larvæ.—It is a fact not altogether unworthy of notice that several species of larvæ are possessed (apparently) of a very spiteful and aggressive nature, while others, as far as one may judge from appearance, are equally good-tempered and amiable in disposition. The larvæ of several of the Sphingidæ are very remarkable in this respect. If kept together, they soon lose the horns, which become disabled in a very short space of time. Then the larva of the puss-moth is also distinguished for its cannibal propensities, and its fondness for using the horns, supposed to be a whip to drive away ichneumons. I have had larvæ of a noctua that have devoured each other, and I was a long time much puzzled by their disappearance, which thus lessened numbers amazingly. Whether this propensity is induced by confinement, which necessitates their close proximity to each other, is not certain; but I am inclined to think so, as it does not seem to be the case wen at liberty on their native trees.—E. C.

Lime Hawk-moth.—Having a brood of Lime Hawk-moths (Smerinthus Tiliæ) in the larva stage of existence, which emerged from the eggs on the 22nd and 23rd of May last, I have noticed them pretty closely. They case their skins for the first time on the 28th and 29th of the same month, and they have just (June 3rd) completed that operation for the second time; but I observed that as they each got clear of their old garment they turned round and ate it up. Thinking this might be one of the "things not generally known," I communicate with you.—A. B. F.

Insects in Armour.—It is well known that in some of the Swedish lakes particles of pure iron are found. Dr. Sjogreen explains this remarkable phenomenon to be due to the larvæ of certain insects, which, like the caddis-worm, cover themselves with a protective coating. The coating is in this case oxide of iron, from which the insects absorb oxygen, and their bodies thus become invested with a complete suit of iron armour.—Day of Rest.

Early Wasp.—I take it for granted that your correspondent R. K. (page 137) is describing a queen wasp. Its appearance on March 17th is not very surprising. Leonard Jenyns, in his "Calendar of Periodic Phenomena," whilst giving April 19th as the average date of its appearance, records one being seen as early as March 3rd. In 1858 I myself saw one on March 23rd, and in 1859 on March 27th, in North Lincolnshire.—J. B. Humber.

Wasps.—"Vespecide" writes that he has destroyed 72 wasps, which he presumed were males as well as females. Now under the impression that all wasps which appear during the months of April and early part of May were queens, on the 22nd of April I offered a premium of 1d. to the garden labourers for every wasp they might bring me up to May 1st, and the result was the destruction of 1,020 wasps, for which I paid £4 5s. I will feel rather vexed to be informed that probably one half were males. Can you, therefore, kindly satisfy me on that point? I may add that I never saw so many large wasps as now exist, even though we destroyed about 200 nests last autumn.—J. M., Addington. [You may make your mind easy respecting the wasps, as males (or kings, as "Vespicide" miscalls them) are only produced in the autumn, and all die before winter sets in. The past and present have been remarkable seasons with reference to the economy of the vespiary. The hot dry summer of 1864 allowed vast numbers of wasps' nests to be formed, and in August the workers swarmed everywhere to an extraordinary extent; but an insidious disease, very similar to that known in the apiary under the name of foul brood, set in at the beginning of the autumn and entirely destroyed the brood of many nests, so that in September we were nearly freed from the winged insects. Many females must, however, have been produced since, as, soon as the warm weather set in in April last, great numbers were seen; but May on the whole was cool, and they then appeared in fewer numbers. A considerable number of the small egg-shaped paper-like nests have, however, already been brought to me; so that if we do not have heavy rains to swamp the underground nests, we shall most probably be as much infested in July and August as we were last year.]—J. O. W.—The Gardener's Chronicle.