IN THE FIELD OF SCIENCE.

Southland Times, Issue 21220, 22 October 1930, Page 6

IN THE FIELD OF SCIENCE.

FIGHTING THE LOCUST. Early this year large areas in Egypt and Palestine were ravaged by locusts. This brings home the fact that there is still a great deal in nature “unharnessed.” We are informed that the insects during their migrations appeared in such numbers that the plague clouds actually darkened the sun’s rays and covered every green thing with millions of hungry individuals. tn a correspondence in a scientific journal some years ago, a writer estimated that a great flight of locusts that he had witnessed crossing the Red Sea covered 2,000 square miles of air, and that the number of insects exceeded 24 billions. He further calculated the weight of the total mass at 42,580 millions of tons, on the . basis that each locust weighed one-sixteenth of an ounce.

The ideal, of course, is to attack the plague at its source, the breeding centres where the females deposit their tubes of eggs just below the, surface of the ground. An interesting feature of the egg-laying is that the female is supported by two males whilst employing her ovipositor in the manner of a road-drill to ensconce her eggs in the ground.' It is not long since similar swarms, some twenty miles long and over one and a half broad, appeared in various parts of South Africa, where they were successfully combated with arsenic and man’s latest weapon—liquid fire.

Experiments are at present being made to fight the plagues by the introduction of parasites that are known to infest and kill locusts, notably certain beetles (Cantharidae) and two-winged flies (Bombylidae. The parasites, it is hoped, will prove even more efficacious than liquid fire and chemicals—remedies which must necessarily add to the havoc of the crops.