No. 432.
Mr. Hoffman to Mr. Evarts.

No. 138.]

Sir: I find in the Journal de St. Petersburg of this morning, extracts from an official report upon the subject of the locusts in Southern Russia. [Page 926] These extracts may interest our board of agriculture, more particularly in connection with the grasshoppers, so troublesome in some of our Western Territories. I therefore send you two copies of the Journal, and a translation of the extracts in question.

I have, &c.,

[Inclosure in No. 138.—Translation.]

Locusts in Russia.

Mr. Portchinsky, secretary of the Russian Society of Entomology, having been sent last summer to the southern provinces of the Empire to ascertain what places grain locusts (anis opolia austriaca) prefer to lay their eggs in, has made numerous researches in the province of Pultava and has come, the Gazette of Agriculture tells us, to the following conclusions:

The grain-locust generally deposits its eggs in wheat-fields, and as soon as they are hatched the attacks of the insects 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 larvae (from 2 to 5) a square archine, but if these fields are near wheat-fields the larvae are then just as numerous.

The fields which have been sown with wheat the preceding autumn are the receptacles of an immense quantity of larvae, which it is impossible to destroy before they have become chrysalids.

The state of the fields whence the owners have driven the locusts is very different. The pursued insects fly in masses to the neighboring fields, and the wheat-field where they have fought these insects does not retain more than 3 to 16 larvae a square archine; on the other hand all the fields of flax, buckwheat, oats, &c., 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 eggs in wheat-fields, where they may be destroyed in the spring while in the state of chrysalids, they settle upon the surrounding fields, no matter what they are sown with.

Experiments made on the spot by Mr. Portchinsky prove that the larvae turned up by the plow 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 larvae (become chrysalids) are in a state of complete immobility, plowing the fields will be of great use, because the chrysalids exposed to the action of the sun will certainly perish.

As to fighting the locusts by destroying its eggs, Mr. Portchinsky considers this to be impossible, inasmuch as the period during which the eggs remain in the ground, before they become larvae, is precisely that during which the grain is standing.

Mr. Portchinsky is convinced that this year the locusts have left only an insignificant number of larvae, which permits us to hope that the crops of 1881 will run no serious risk in this respect.

As to next year, according to the researches he has made in three townships, the fecundity of the locusts has been very great.

He concludes that as the wheat-fields of last year contained 20 to 50 larvae a square archine, we get, counting only an average of 30 larvae a square archine, a total of 648,000 locusts to the “deeiatine,” (.37 of an acre). In the village of Kroutoyar, where the wheat-fields cover 200 deciatines, each archine contained at least 50 larvae. It follows that these 200 deciatines will contain next year more than 2,000,000 of locusts, and that consequently, if the spring of 1880 is favorable to the increase of this insect, we must unfortunately expect great ravages from it.