35 



to my inquiry on this point* were received from Northern Illinois, 

 of which 30 were affirmative (77 per cent.); 54 from the Central 

 part of the State, of which 40 were affirmative ( 74 per cent. ) ; and 

 117 from Southern Illinois, 105 affirmative (90 per cent.). 



EXPERIMENTS. 



Fertilization. — The fact that the chinch-bug attack affects most 

 seriously the vegetation of the poorest soils, that crops on rich 

 land will often escape damage while those on poor land adjoining 

 it may be completely destroyed, is well enough known from com-^ 

 mon observation. Not unfrequently different areas in the same 

 field will illustrate this difference in unmistakable terms, especially 

 if some parts of the field receive the "wash" from others. The lack,, 

 however, of precise evidence respecting the degree of benefit to be 

 derived in an infested region from the use of fertilizers as a sup- 

 port to the crop against chinch-bug attack, led me to undertake, 

 in 1887, a field experiment. Through the kindness of Samuel 

 Bartley, Esq., of Edgewood, Effingham county (who gave the 

 matter his personal care throughout the season), I was enabled to 

 to make this test on a small field of his wheat. 



This plot, after plowing in fall, had received a top dressing of 

 manure taken from stock yard, stable, hog-pen, and poultry house,, 

 the ground never having been fertilized before. On the 3d 

 of May I found an extraordinary number of adult chinch bugs in' 

 this wheat, just beginning to lay their eggs. So overwhelming, 

 ing was their attack that Mr. Bartley compared the noise of their 

 flight, as they entered the grain, to that of a swarm of bees. 

 Even at this early season the wheat was seriously affected, the 

 plants reddened and dwarfed in patches, and the growth dimin- 

 ished, as I estimated, about one third. On a measured part of this 

 plot, commercial fertilizers were sown at the rate of one hundred 

 pounds each per acre of nitrate of soda, superphosphates, and sul- 

 phate of potash. The wheat from both parts of the field was har- 

 vested and threshed by hand, kept carefully separate, measured, 

 and weighed, the general result being that for the portion ferti- 

 lized with barn-yard manure alone, the yield, notwithstanding the 

 enormous attack by the chinch bugs and their continuance 

 throughout the season, amounted to 20.8 bushels per acre of wheat 

 that weighed 54 pounds to the bushel; while that treated with 

 commercial fertilizers in addition, yielded at the rate of 24 bushels 

 per acre of grain weighing 62 pounds to the bushel. The result 

 of this experiment was especially noteworthy, as 15 bushels per 

 acre is considered in that region a good average crop. On another 

 field of badly worn land less than half a mile from our experi- 

 mental plot, (the only other wheat in the neighborhood,) a simi- 

 lar application of the commercial fertilizers, produced a marked 

 improvernent in the beginning of the season, in size and color of 

 the plant, but later the whole succumbed to the chinch-bug. 



• See p, 11. 



