69 
spring-plowed areas on each side are overrun with the depredators, 
and the crop seriously injured. 
The year has also been marked by the excessive abundance of the 
Hessian fly and especially in early sown fields, the later sown not suf- 
fering except where located near early sown fields, and in this case the 
attack seems not to have fallen on the plants in the fall, as the fields 
then appeared uninjured, but during the spring, thus indicating a 
Spring migration of the females from the early to the late sown fields. 
The wheat midge, Diplosis tritici, which occurred last season in some 
abundance, reappeared the present year in still greater abundance. 
Although the injury, both last year and this, was limited wholly to 
later maturing wheat, there seems to be at least a possibility of a still 
more serious outbreak next year. Our advice to farmers to sow late 
this fall to avoid the Hessian fly is m some cases likely to be disre- 
garded through fear of thus inviting the attack of the wheat midge, 
while, as a matter of fact, the early and late sown wheat ripen almost 
simultaneously, as was very clearly illustrated on the experiment sta- 
tion grounds the present year. 
Diabrotica longicornis continues to push its way eastward across the 
- State in destructive numbers. It is only within recent years that it — 
has been possible to find the insect at all in the vicinity of Columbus. 
Now, the valley of the Scioto River, from here to the Ohio, is noted for 
its vast cornfields. There is one field in particular, situated near the 
mouth of the Scioto, that is known to have been planted to corn con- 
tinuously for over a century and until now has never been affected by 
this pest. Within the last few weeks from points all along the Scioto 
River below Columbus there have come reports of the depredations of 
these insects. While these complaints have been that the beetles have 
eaten off the silk before the kernel has been fertilized, anyone who is 
familiar with the pest will understand that the work of the larve on 
the roots of the plants has much the same effect in foreshortening the 
ear. While the problem of fighting this pest is under ordinary condi- 
tions a simple one, the Scioto Valley offers some obstacles to the rota- 
tion of crops not encountered elsewhere in Ohio. At the mouth of the 
Scioto there is a wide flat bottom, about 2 miles wide by probably 3 or 
4 miles in length, that is covered for a considerable time in spring, and 
occasionally at other times, by backwater from the Ohio. In spring 
this does not disappear until it is usually too late to devote the land to 
any grain crop other than corn. The difficulty here will be to find a 
crop with which to rotate in order to exterminate the pest. 
The onion thrips, Thrips tabaci, has been excessively abundant in 
some sections, notably in the extensive onion fields in Wayne and 
Hardin counties. While this pest is with us every year, its abundance 
seems to depend upon the lack of precipitation during July and early 
August. Recent experiments have shown that the insect can be 
destroyed by the application of a whale-oil soapsuds, using 1 pound of 
