1. Injury to farm crops may be caused by grasshoppers in every part of South Dakota, but the damage is ordinarily done in alfalfa fields and in areas bordering such fields.
2. The locusts which are responsible for the damage are reared usually in alfalfa fields or along the borders of these fields and are not of the migratory kinds.
3. Locusts are held in check ordinarily by various natural agencies, but when these are lacking, the grasshoppers tend to increase in large numbers. If an outbreak of hoppers is to be prevented under these circumstances, artificial methods of control must be adopted.
4. In the fall of the year, after October 15, such areas as contain grasshopper eggs should be plowed, and in the spring the soil should be disked, harrowed and rolled, so as to pulverize and pack the ground. If the ground cannot be plowed in the fall and if spring plowing is possible, then this should be done before May 15. The plow should be followed by the disk, harrow and roller. If the ground is not to be plowed, then it should be disked, harrowed or cultivated in the fall, and in the spring it should be thoroughly harrowed. If in the spring, there a.re numerous grass clumps in the field, and if these clumps contain uninjured grasshopper egg masses, the field must be thoroughly worked with a brush harrow or plank drag.
5. As soon as the grasshopper eggs have hatched in the spring, the young hoppers should be killed with poisoned bait. Poisoning should not be delayed until the hoppers are mature or almost mature, for considerable injury will have been done by the immature locusts by that time.
6. The use of the hopper catching machine and the hopperdozer are two effective methods of reducing a plague of locusts, and these machines, if they are employed at all, should be put in operation while the locusts are still small.
7. Other methods of locust control, such as burning the young hoppers, destroying them with poultry, etc., are aids in reducing the number of insects rather than very effective means of destruction.
8. Cooperation is usually an essential factor in grasshopper control.
South Dakota State College of Agriculture and Mechanic Arts, South Dakota Agricultural Experiment Station, Department of Entomology, Grasshoppers, Insecticides, Locusts
South Dakota Experiment Station, South Dakota State College of Agriculture and Mechanic Arts
Severin, H.C. and Gilbertson, G.I., "Grasshoppers and their Control" (1917). Agricultural Experiment Station Bulletins. 172.