BUTTERFLIES AND LOCUSTS.
“The Death’s-head is said to be the largest moth we have, and is, in fact, the largest found inhabiting Europe, save the Peacock moth. Be this as it may, it is a very large insect, measuring from five to six inches across the wings, and having a body proportionately long and thick. The caterpillar, which is smooth, and of a greenish-yellow, with minute black dots all over, and with seven or eight bluish stripes on the sides, having a horn above the tail, is likewise very large,—being, when full grown, about six inches long. It feeds on the potato, the deadly-nightshade, the jasmine, and the Lycium barbarum, and other plants of as dissimilar a nature.”
In another article he mentioned the Herald Moth (Scaliopteryx libatrix), a specimen of which was presented to him by Mrs. G. Bannerman. He describes this beautiful insect as occurring in great profusion in some of the southern parts of England, but as very rare in the north. It is called the “Herald” moth, because it is said to indicate the approach of winter.
LOCUSTA MIGRATORIA.
The Peacock Butterfly (Papilio Io), was caught in Duff House garden, close to Banff. Although common in England, this butterfly is very rare in Scotland. Morris makes no mention of its ever having been seen in the north. A great flock of these butterflies passed over a part of Switzerland in 1828, when they were described as a swarm of locusts. This circumstance led Edward to insert some observations regarding that destructive insect, the Locusta migratoria, which passed over this country in the year 1846, the ever-memorable potato-famine year.
“Great numbers,” he says, “were found in the counties of Aberdeen, Banff, and Moray. Several were also got in the sea at Aberdeen, as well as near Banff. Some of those found were very large, being two and a half inches long, and nearly as thick as one’s little finger; their wings expanding to about four inches in breadth. Nine of this size were found by one individual in a turnip-field at the Stocket, near Aberdeen. They were brought to me while I was there with my first unfortunate Collection. But, large though this may seem, it is nothing to others. We are told that in India there are locusts of a yard in length. I do not vouch for the fact; it is no story of mine. Pliny tells it; and from him we have it. Some found in the sea at Aberdeen were offered there for sale as ‘fleein’ fish,’ and no less a sum than ten shillings was sought for them. Strange sort of flying-fish this! Truly it may have been said that the entomological and ichthyological schoolmasters were both abroad in those days. It may, however, be remarked, that something of a similar kind took place amongst ourselves not very long ago, so that we have little room to laugh at the Aberdonians. A person having picked up a galerite (a species of fossilised sea-urchin of the Cretaceous system), near by our harbour, was showing it to some individuals, when one of them, no doubt puzzled, said, ‘O! it’s just something that somebody has made.’ But to return to the locusts. Those of which we have been speaking arrived in the month of August and the beginning of September. Now, this year it would appear that something of the same kind had taken place, as numbers have been picked up in various parts of the country. Three have, at least, been found with us, viz. two near the Moss of Banff, and one at Cornhill; another at Mintlaw, Aberdeenshire. I have also one from Lerwick, where it is said they have been rather plentiful in the corn-fields; as also in the Zetland Islands, in Unst, and the rest of the bare and isolated Skerries. In some of the Western Isles, I believe, they have actually proved a complete pest.
THEIR DESTRUCTIVE POWER.
“As may be expected, there are many species of this creature, as there are of everything else: but those here alluded to are perhaps the most redoubtable of them all, as being the most destructive, the best known from their migratorial flights, and being, as already hinted, the species that constituted one of the awful plagues of Egypt in the days of Moses. They were doubtless the same that wasted the land of Canaan, and caused such a terrible famine, of which we read in the book of Joel. A wind drove them into the sea; their dead bodies were again cast on shore in such heaps that the Hebrews were obliged to dig large pits in which to bury them. In this country, we have about twenty-five different kinds belonging to the same family, of which the foregoing is one; but of course they are all of small size, and therefore may be said to be comparatively harmless.”
SAW-FLIES.
In another article, Edward mentions another insect almost equally destructive. A friend of Edward at Turriff found four Saw-flies in a piece of a fir tree that was being cut up for firewood. They are called Saw-flies “from the fact that the female possesses, posteriorly, an instrument by which she perforates, or rather saws, holes in trees, into which she drops her eggs. From this it will be seen that the larvæ are woodfeeders. In this country they are by no means numerous, and it is well that they are not, or our forests would shortly disappear; for, in places where they abound, such as in Norway, they destroy hundreds of thousands of trees in a season. It is only the growing and not the dead wood that they attack. The young grubs, as soon as they emerge from the egg, cut their way right into the very heart of the solid timber, and there they gnaw and bore in every possible direction. By this means, the tree is either killed, or so injured, that ultimately it pines and dies. The fly itself has no English name, but is known to entomologists by the term of Sirex juvencus.”