426 



AN ECONOMIC ENTOMOLOGY. 



Sometimes, where land cannot safely be left bare during the 

 winter, it may be ploughed earlier, and some catch crop, simply 

 to cover the surface, can be put in, and it matters very little what 

 this is. It may be crimson clover, rye, wheat, — anything, in 

 fact, to get a covering, provided it is something radically different 

 from what was on the ground before the ploughing was done. 

 Corn-fields should be treated in this way after the crop has been 

 harvested, if late ploughing is undesirable, for it is always a mis- 

 take to leave them unturned until the spring following. It is 

 a good plan, just as soon as one crop is off, to put in some- 

 thing else, which, as already suggested, should be quite different 

 in general character ; and this brings up the question of rotation. 

 It is impossible to make any generally applicable statements on 

 this subject. No two regions of our country are entirely alike in 

 their practice, in the crops raised, or in the rotation adopted ; 

 but so far as possible a rotation should be selected which will 

 keep the ground covered all the time, the crops that follow each 

 other being unlike in their natural family, — that is, grass should 

 not follow wheat or rye, if it can be avoided ; nor should potatoes 

 be followed by egg-plants or tomatoes ; or cabbages by mus- 

 tard or radishes ; but in all instances crops as diverse as may be 

 should follow each other, and as rapidly as possible. Where 

 wire-worms are the chief sinners, crimson clover may sometimes 

 be usefully employed. Plant this in fall, and in spring it will be 

 in excellent condition to attract the adults to lay eggs. Turn it 

 under late in May or early in June, after cutting for hay or as a 

 green manure, and plant any suitable crop. The very young 

 larvae will be incapable of doing injury, and will fail to maintain 

 themselves under the new conditions. It must be remembered, 

 however, that this practice will favor cut-worm increase, and 

 measures must be held in readiness for these when the planted 

 crop makes its appearance. 



Another good plan is to have a considerable number of 

 chickens, and to train them to follow the plough. This can be 

 very easily done, and after a few are once trained, they will in 

 turn teach the entire flock, while the young learn readily from 

 the older. Chickens following a plough will pick up almost 

 every insect that is turned up, be it in the larval, pupal, or adult 

 condition, and they are especially effective in fields infested by 



