82 INSECTS INJURIOUS TO VEGETABLES 



METHODS OF CONTROL 



No application that can be made to the soil will kill the wire- 

 worms without, at the same time, rendering the land unfit for 

 cultivation for some time afterward. 



Most remedies, preventives, repellents and poisons that have 

 been tried are hardly more than palliative. From among these 

 the ones that give most promise are early fall plowing, the use 

 of poisoned baits early in the season, with the selection of un- 

 infested land for planting, and rotation of crops. We are in 

 fact confronted with much the same problems as in the treat- 

 ment of white grubs, only wireworms are even more difficult 

 of suppression. 



Selection of land for planting —The most important of de- 

 fensive methods is the selection of the land for planting. 

 It is inadvi-sable to plant crops peculiarly subject to wirevvorm 

 attack, such as corn, potatoes, and other vegetables, as well as 

 cereals in sod land or in unbroken prairie, and it is equally 

 unwise to'^cultivate such crops in fields in which wireworms 

 are known to be present. 



Fall plowing. — Infested or "suspicious" soil should first be 

 prepared for the crop by plowing early in the fall. By this 

 process the cells in which the pupae and hibernating adults are 

 resting are broken up and the insects destroyed in great num- 

 bers, so that fewer individuals survive to deposit eggs for an- 

 other generation of wireworms the following year. Such as 

 are not destroyed outright by this method will be more exposed 

 to the elements and to predatory enemies. 



Crop rotation should also be practiced in the same manner 

 as prescribed for white grubs. In addition to clover, buckwheat 

 is said to be a valuable alternate because of the roots being too 

 tough and hard to be injured, and possibly this is true of some 

 forms of wireworms, but not of all, so we cannot place much 

 reliance on this crop. If clover or other alternate be allowed 

 to remain for one or two years after grass has been cut, veg- 



