EFFECTS OF HARROWING IN AUTUMN. 355 



utilizable air than we can by the nse of water, which will be presently 

 considered. The breaking up of the mass and exposure of the iudi- 

 vidual eggs to the desiccating effects of the atmosphere effectually de- 

 stroys them, and when to this is added the well-known fact that, thus 

 exposed, they are more liable to destruction by their numerous ene- 

 mies, we see at once the importance of this mode of coping with the 

 evil. 



Harrowing in the autumn, then, 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. It should 

 be enforced by law, as we shall presently suggest in considering legis- 

 lative action, whenever the soil in any region is known to be abundantly 

 stocked with eggs. A revolving harrow or a cultivator will do excellent 

 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. Where the cultivator is used, it would be well to pass 

 j)ver the groun.d again with a drag or a brush harrow for this ijurpose. 

 Some of our correspondents have urged, and with some reason, that 

 wherever land can conveniently be prepared to induce the females to 

 oviposit in it, as by plowing and then rolling when the insects are be- 

 ginning to breed, such preparations should be made. A subsequent har- 

 rowing will be the more easy. In practice, this method will not often be 

 adopted, because it will pay only under exceptional circumstances. 



We give here a few of the views of correspondents on the subject of 

 harrowing expressed during the past year: 



Harrowing has been tried with success, especially when fowls, swine, &c., have been 

 given access to the ground. In one case, a piece of two acres was entirely freed from 

 the eggs in this way. — [Robt. Milliken, Emporia, Kans., September 15, 1877. 



Harrowing the ground in the fall is always beneficial ; it brings many of the eggs 

 to the surface, where they are picked u]) by birds and fowls and otherwise destroyed. — 

 ^E. Snyder, Atchison, Kans., June 20, 1877. 



The reports of the results of this latter method of destruction are conflicting, varying 

 according to the care expended upon the work, the lateness of the season at which it 

 was done, and the accuracy with which the results were noticed. 



In cases where new breaking thickly filled with eggs was passed over once or twice 

 with a seeder in November or late in October, a portion of the eggs were left undestroyed, 

 and these, hatching in the spring, the young devoured the grain as fast as it grew. In 

 other cases eggs brought to the surface late in the fall retained their vitality (the 

 young were fully formed in the eggs) during the winter; but afterward, when they 

 had been fully exposed in February and March to alternate heat and cold, without a 

 coveriug of snow, only a small fraction of them could be hatched. In other cases, 

 where the number of eggs was not excessive, the proportion of eggs left undestroyed 

 after fall harrowing was too small to cause (of themselves) any serious damage in the 

 spring. From all the inquiries that I have been able to make during the season, I am 

 confirmed in the statement made last year, that it is desirable to bring the eggs to the 

 surface at the earliest possible moment after there is any assurance that the laying 

 season is over; in other words, they should be exposed to tlie sun while their contents 

 are still fluid. — [Mr. Allen Whitman, special assistant. 



Some eggs were harrowed up during mild weather in winter and greedily devoured 

 by tame fowls. Some egg-masses that were exposed in February mostly hatched. — [G. 

 B. Brown, Guilford, Kans. 



Harrowing the ground in the fall is good ; every egg-mass that is broken or brought 

 to the top is used up. Last fall was an unusually wet one, and great numbers of eggs- 



