OJF THE FARM AND GARDEN. 275 



from hatching to full development varies according to 

 season and weather, cold and wet weather retarding, and 

 warm weather accelerating development. It averages, 

 however, two months. There is but one generation each 

 year, the term of the insect's life being bounded by the 

 spring and autumn frosts. 



Of the various methods of combating the attacks of 

 this Grasshopper, we have 



THE DESTRUCTION OF THE EGGS. Harrowing in the 

 autumn, or during dry, mild weather in early winter, 

 will prove one of the most effectual modes of destroying 

 the eggs and preventing future injury, wherever it is 

 available. A revolving harrow or a cultivator will do ex- 

 cellent service in this way, not only in the field, but 

 along roadways and other bare and uncultivated places. 

 The object should be, not to stir deeply but to scarify and 

 pulverize as much as possible the soil to about the depth 

 of an inch. 



PLOWING. Next to harrowing this is one of the most 

 generally available means possessed by the farmer of 

 dealing with locust-eggs. 



IRRIGATION. This is feasible in much of the country 

 subject to locust ravages, especially in the mountain 

 fields or gardens. 



COAL-OIL. The use of coal-oil and coal-tar may be 

 considered, as both substances are employed in various 

 ways for trapping and destroying the insects. Coal-oil is 

 the very best and cheapest that can be used against the 

 locusts. It may be used in any of its cruder forms, and 

 various contrivances have been employed to facilitate its 

 practical operation. The main idea embodied in these 

 contrivances is that of a shallow receptacle of any con- 

 venient size (varying from about three feet square to 

 about eight or ten by two or three feet), provided with 

 high back and sides, either mounted on wheels or run- 



