300 INSECTS 



toes, hand picking is the best and most reHable method. 



So, when borers get into om- peach trees, the only 

 really effective way is to go after them with a knife, 

 and if apple or similar round-headed borers are in 

 fault, a soft wire is added to the outfit to reach such 

 insects as have gotten into the heart wood. 



Against species that march we erect barriers of one 

 kind or another. Army-worms and chinch-bugs, for 

 instance, may sometimes be stopped by running a 

 ditch across their path or a couple of plowed furrows 

 with steep sides to prevent their easy ascent. At 

 intervals in these furrows post holes are driven and as 

 the insects crawl along the bottom of the furrow or 

 ditch seeking a way out, they fall into the post holes 

 and are treated to a dose of kerosene. Myriads of 

 specimens are often killed off in such campaigns, and 

 the farmer saves his crops, without perceptibly de- 

 creasing the number of his foes for the year to come. 



Some species we are able to circumvent by a httle 

 adaptation of our farm practice. For instance, where 

 com is raised continuously on the same land in the 

 middle west, the corn-root worm soon becomes a serious 

 pest; but if every third year the land is put into some 

 other crop, no harm ensues because the insects in the 

 old cornfields are starved out. We have learned that 

 rotation of crops is a good thing, and try to avoid plant- 

 ing two successive crops of a similar kind; or if that 

 cannot be avoided, planting or plowing so as to avoid 

 harm. For instance, corn following old timothy is bad 

 practice where the latter is liable to be infested with 

 bill-bugs. Corn belongs with the grasses, and the bill- 

 bugs finding no timothy when they emerge, attack the 

 corn. If the succession cannot be avoided, the soil 

 should be plowed in fall and the com planted as late as 

 may be. Similar practice is to be followed where root 



