GRASSHOPPERS
Grasshoppers are a source of no little loss to alfalfa growers in some parts of the West. They usually do their greatest damage to the season’s second crop, the young not being very destructive to the first. The best remedy, or rather prevention, is deep disking in April and then harrowing to destroy the eggs.
Where the pests attack or are about to attack a field of alfalfa, Prof. L. Bruner, of the Nebraska station recommends the use of a “hopper dozer,” which is “simply a long, shallow pan of stove-pipe iron or galvanized iron mounted on runners and backed by a light frame covered with cloth. The pan is about four inches deep, from eighteen inches to two feet wide, and from ten to sixteen feet long. It is partly filled with water and a little kerosene. A horse drags the machine across the field over the stubble of the first crop and the half-grown hoppers jump into the pan where the oil coats them over and kills every one that it touches. The hopper dozer works best on level land. On sloping ground the oil and water run to one end and slop over. To prevent this the pan is usually divided into sections by a number of partitions. The runners should stick out in front of the pan about a foot and one-half, and a piece of chain or heavy rope should be stretched loosely between them to drag ahead of the machine and make the hoppers jump. On level fields there are no great difficulties in the use of the hopper dozer. Careless driving may spill oil on some alfalfa and kill it. If these machines are to be really effective, they must be used before the grasshoppers get their wings. The first crop of alfalfa should be cut as early as possible, and the hopper dozers should follow the rakes as closely as may be. On the whole, they should be used only where plowing and harrowing have not been done or have failed to keep the grasshoppers in check.”
Of the use of this implement or machine Prof. S. J. Hunter has this to say:
“The height of the runners depends upon the height of crop to be protected. It is important that there be no timbers in front of the pan, so that its front line may come in contact with the grain passed over. The insects then fall directly into the fluid. When ready for use place two buckets of water and one-half gallon of coal-oil in a pan, and then drive back and forth across the end of the field where the grasshoppers are entering until you have filled the pans; remove the insects, replenish with oil and water, and continue until the field is rid of the pest.
“Many grasshoppers will be seen strike the sheet-iron back, drop into the pans and immediately jump out again. Those farmers who observed the experiments were at first of the opinion that the locusts that jumped out had jumped away ‘to live another day.’ The writer asked those interested to watch the insects and note the actions of grasshoppers that had jumped out. In every case the report was that the insects became sick and soon died. In fact, persons going over fields where a day or so before the hopper dozer had been at work, were impressed with the number of dead grasshoppers on the ground. An examination showed the presence of coal-oil upon the body. This kerosene and water is an external irritant, and my observations have been that the mixture is more effective than the oil alone.
“The use of the machine may be best shown by examples. In Ford county, Kansas, a large tract of alfalfa was cut, and the locusts at once began moving into a large field of Kafir corn which had been sown broadcast. The hopper dozer was drawn back and forth across the end of the corn field nearest the alfalfa land until a portion of the field about twenty rods deep had been gone over. Here it was apparent that there were very few grasshoppers; or, in other words, the advance line of the locusts’ march only extended twenty rods into the field. Two days later the same area of ground was covered, but not as many insects were taken. Grasshoppers no longer entered this corn and the hopper dozer was no longer used at this point.
“It has been my experience with this machine that after it has passed over vegetation it does not injure the plants, but in some way renders the vegetation distasteful to the grasshoppers, so that they turn their course and seek food elsewhere. I have observed that these native grasshoppers enter a field from one corner or side, and that they are not as a rule scattered over the whole field, but occur in great numbers in patches. This being the case, it is evident that with very little labor with this machine the products of a field can be given full opportunity to mature.”