Locusts of Australia are species 'of Tettigonim or tree-hoppers, all of a green, ora4, brown, or black colour, with membranous wigs remark able for their iridescence. Their names are the Cicada mcerens and C. curvirostra . the orange spotted Tettigonia, Fidicina angula;is ; the Cylo chila Australasia; the Thopa saccata. Some of them are partly covered with a whitish secretion, and get the names of millers and bakers ; and the Cylochila Australasia are called lamplighters by the boys, from three ruby-coloured spots on the front of the head.
In 1813 Marseilles expended 20,000, and Arles 25,000 francs for the destruction of injurious insects. The hunt commenced in May, and almost the whole population of certain villages were employed in it. A cloth of coarse web is carried by four men, one holding each corner. The two who walk first make the foremost edge of the cloth sweep the ground, and the insects leap into the cloth, where they are caught as in a bag. A small bag at the end of a stick, like an ento mologist's bag-net, is also used. The females lay from August to October, the eggs being placed in holes in the earth in a cylindrical tube of glutinous matter covered with a thin envelope of earth (exactly as stated by Aristotle). The tube is about an inch and a half long by 3 or 4 lines wide, and placed horizontally. Each tube contains from 50 to 60 eggs, and a child trained to the work can collect 10 to 14 pounds per diem, each pound con taining about 800 eggs. In other places carts are driven up and down over the breeding grounds with the object of destroying the egg-pouches by crushing them into the earth.
Mr. Taylor says the Turdus roseus, called by the Mesopotamian Arabs Sammir-med, destroy great quantities of locusts by cutting them in two. They seem to be the Seleucidm of Pliny, which, consequent on the prayers offered up to him by the people of Mount Casius, were sent by Jupiter to destroy the locusts ravaging their corn crops (Pliny, book x. ch. 39). In Central India locusts are destroyed by digging trenches for them to fall into. As they spring from eggs deposited by previous flights of locusts, when hatched they hop along in dense masses while yet unfit for flight, and in their progress lay .waste all vegetation. In Bikanir they dig trenches to leeward of where these young broods appear, and take measures to drive the locusts into them, and the sides being perpendicular, the creatures hop in, but cannot hop out, and earth is thrown in upon them. A resident at Ajmir on one occasion adopted this plan. He sari : In about two hours we succeeded in getting several trenches dug, varying from 25 feet to 60 feet long, 1 foot wide, and about 2 feet deep. Then we sent native soldiers in a horse-shoe direction from the trench about 1000 feet away to wave hands and drive the locusts on. They came, and thickened as they approached, one dense mass, hopping along till they hopped into the trench. It was a curious sight to stand at the end and look at it all,—a seething, hopping mass inside the trench, while a regular short cataract came pouring down on to them until they were about two inches deep, then the hopping ceased in the trench. They had nothing bard to kick against, but the influx continued till they were half up the ditch, when we quickly threw in earth and buried them, and then off to another trench and repeat the whole operation. We continued
this for two hours. While at one of the trenches, I sent for a finger-glass, and immersed it in the mass of locusts, as one might dip it into water, then struck it off with a piece of cardboard, so I had it as full as it would hold. When I got home I weighed tho glass full, then emptied it and weighed the glass, so I got the weight of the locusts ; then I counted them out (566), then measured very accurately the solid contents of the glass, by weighing the amount of water it held, and computing from that ; thus I had space, number, and weight for data. Knowing we had dug and tilled 300 feet of trench one foot wide, filled to one foot deep, I calculated, and J—, S—, and C— checked the calculations with me : result, killed and buried, 7f millions of locusts, weighing 10i tons, in two hours from the time the trenches were ready, about four hours altogether! After such results ought any district to be thus infested ?' Mr. Portchinsky, secretary of the Russian Society of Entomology, was sent to the southern provinces of the empire to ascertain in what places grain locusts (Anisoplia Austriaca) preferred to lay their eggs, and ho came to the following con clusions :—The grain locust generally deposits its eggs in wheat-fields, and so soon as they are hatched the attacks of the insect on the grain commence. There are generally from 20 to 50 locusts per square archine (an archine is 27 inches) of wheat. Rye and barley fields contain comparatively much fewer lame (from 2 to 5) a square archine, but if these fields be near wheat fields, the lame are then just as numerous. The fields which have been sown with wheat the pre ceding autumn are the receptacles of an immense quantity of la.rvm, which it is impossible to destroy before they have become chrysalides. The state of the fields whence the owners have driven the locusts is very different. The pursued insects fly in masses to the neighbouring fields, and while the wheat-field where the owners have fought them does not retain more than 3 to 16 larvm a square archine, adjoining fields of flax, buck wheat, oats, etc., which are not generally attacked by the locusts, become infested, and contain from 16 to 26 larvae an archine. It follows that the use of ropes or machines to drive away the locusts is very dangerous, because, instead of laying their eggs in wheat-fields, where they may be destroyed in the spring while in the state of chrysalides, they light upon the surrounding fields, uo matter what they are sown with. Experiments made on the spot by Mr. Portchinsky prove that time larvm turned up by the plough re-enter the earth quickly, but if they can be kept exposed ten minutes to the sun, they infallibly perish under its heat. He concludes that in the spring, when the larvm (become chrysalides) are in a state of complete immobility, ploughing the fields will be of great use, because the chrysalides, exposed to the action of the sun, will certainly perish. As to fighting the locust by destroying its eggs, Mr. Portchinsky considers this as impossible, inasmuch as the period during which the eggs remain in the ground before they become larvm is precisely that during which the grain is standing.