21 



3. The facts presented in this table certainly support the idea — 

 confirmed by many recent observations— that, where circumstances 

 so favor the chinch bug that it passes beyond the stage of a gen- 

 eral dependence on a large wheat area, it finds first in oats and 

 later in grass, a sufficient support for its maintenance, and even 

 for its more or less rapid increase. It is certainly a circumstance 

 to challenge the attention of the student of this subject that an 

 enlarging acreage of oats has invariably gone along with an in- 

 creasing damage to every crop in Southern Illinois, while the 

 wheat area has there increased with the corn injury, stood still 

 with increasing injury to grass, and diminished with the growing 

 damage to small grains themselves. 



Table XII. 



The Whole State, 812 Tomis. Injury to Small Grain, 1887, com- 

 pared with Crop Areas for the Same Year. 



Degree of Injury. 



No. of 

 Tps. 



Wheat. 



Barley. 



Rye. 



Oats. 



Corn. 



Grass. 



None 



392 



1,184 



43 



185 



2,724 



5, 250 



6,652 



Little 



154 



1,432 



54 



173 



2, 743 



4,905 



6,387 





62 



2, 146 



103 



126 



2,057 



3, 445 



4,481 



Considerable 



93 



2,700 



12 



54 



1,902 



3,125 



3,631 



Great 



34 



2, 650 



56 



80 



1,835 



2,996 



3,798 



Very great 



55 



2,621 



4 



34 



2,166 



2,925 



3, 378 



Nearly complete 



16 



1,727 



23 



13 



2,240 



2,932 



3, 155 





6 



1,110 





7 



3,042 



3,008 



5, 014 

















The table for the whole State amounts, as before, to but little 

 more than a recapitulation of the exhibits for the several sections, 

 the wheat areas rising with increased injury to wheat and oats 

 where the central and northern figures preponderate, as in the 

 lower grades of injury, and falling where the series comes under 

 the controlling influence of the Southern Illinois reports. 



COMPARISON OF THE CROPS FOR 1886 AND 1887. 



Tables of the crops for 1886 were prepared of the same number 

 and character as those for 1887, with a view to determining the 

 drift of agricultural practice and its possible relation to the ap- 

 pearance and development of the chinch bug; but after a careful 

 study of these tables in comparison with those for the following 

 year, they do not seem sufficiently important to make their de- 

 tailed treatment necessary. 



The main features of difference were a great general increase in 

 the wheat area for 1887 (twenty-five to thirty-five per cent.) in 

 both Southern and Central Illinois, except in those districts where 

 the chinch bug was most destructive. There, possibly because of 

 a similar serious loss in 1886, the wheat acreage had been reduced 

 by ratios varying from ten to twenty-five per cent., — much more, 

 however, in regions where small grain had been destroyed than 

 where the corn was a total loss. 



