Gen. Pope, Pest Commander at Fort Leavenworth.has a plan of his own for the extermination of the gzasj-hoppers. All the available men at the Fort are put to the work of driving the pests iuto one large heap, when steam from the fire engine is turned upon them. A government wagon load of dead victims was dumped into the river Sunday afternoon. Whether it makes any perceptible diminu tion in the numbers of the wingless plagues we are not informed.