Grasshoppers, tree crickets, and katydids always cause some injury to tobacco in southwestern Ontario, and at times the injury is very severe. Thc leaves may be riddled or even completely stripped, the most severe injury usually occurring late in the season, about harvest time. These insects breed in sod, in wood-lots, and along roadsides, and such areas require special attention when control measures are undertaken. Because it is usually considered advisable to restrict the amount of insecticide applied to tobacco leaves, the chlordane dust used in this experiment was applied only to the vegetation bordering the field. Any control by applying poison to tobacco plants can be effected only after at least limited feeding and some injury to the leaves; but treatment of field margins uses waste plans as the poison ‘carriers’ and a large part of the injury to tobacco is avoided. This method of control is useful only for insects which feed on general vegetation and would be of little value in controlling species which restrict their feeding to the cultivated crop.