Page:Insects - Their Ways and Means of Living.djvu/49

 morrow comes, and, ah! what a change it brings! The fertile land of promise and plenty has hecome a desolate waste, and old Sol, even at his hightest, shines sadly through an atmosphere alive with myriads of glittering insects.

Even today the farmers of the Middle Western States are often hard put to it to harvest crops, especially alfalfa and grasses, from fields that are teeming with hungry grasshoppers. By two means, principally, they seek relief from the devouring hordes. One method is that of driving across the fields a device known as a “hopperdozer,” which collects the insects bodily and destroys them. The dozer consists essentially of a long shallow pan, twelve or fifteen feet in length, set on low runners and provided with a high back made either of metal or of cloth stretched over a wooden frame. The pan contains water with a thin film of kerosene over it. As the dozer is driven over the field, great numbers of the grasshoppers that fly up before it either land directly in the pan or fall into it after striking the back, and the kerosene film on the water does the rest, for kerosene even in very small quantity is fatal to the insects. In this manner, many bushels of dead locusts are taken often from each acre of an alfalfa field; but still great numbers of them escape, and the dozer naturally can not be used on rough or uneven ground, in pastures, or in fields with standing crops. A more generally effective method of killing the pests is that of poisoning them. A mixture is prepared of bran, arsenic, cheap molasses, and water, sufficiently moist to adhere in small lumps, with usually some substance added which is supposed to make the “mash” more attractive to the insects. The deadly bait is then finely broadcast over the infested fields.

While such methods of destruction are effective, they bear the crude and commonplace stamp of human ways. See how the thing is done when insect contends against insect. A fly, not an ordinary fly, but one known to entomologists as Sarcophaga kellyi (Fig. 10), being named after Dr. E. O. G. Kelly, who has given us a