WiREWORMS. 85 



It was found that the beetles were the most active at night, and 

 that they seek their food chiefly by running over the surface of the 

 ground. 



When it was foand that they were so readily attracted to the 

 baits, poisoned clover baits were used with the result that most of 

 the click-beetles were destroyed, proving that they fed upon the 

 baits and thus suggesting a practical method of combating them. 

 "Where the insects are very numerous over a limited area, many of 

 the beetles can be killed with the expenditure of a very little labor 

 in distributing these poisoned baits. 



Ontrap])ing hy lanterns. — A series of six trap-lanterns were 

 kept lighted every night here on the University farm from May 1st 

 to October 1st, 1889. During the whole live months only eighty 

 click -beetles were captured. Thus the method has no practical 

 value in fighting wireworms. 



General Summary of the Methods of Combating Wireworms. 



When we began our experiments in 1889, we confidently expected 

 to be able in a short time to tell farmers how to protect their seed 

 and their growing crops from these pests. We thought that the 

 greatest part of our work would be to determine which of several 

 ways is the most practicable, the easiest used, or involved the least 

 labor or expense. For three years we did our best ; and we failed 

 to discover a single satisfactory method of protecting seed, or of 

 destroying immature wireworms in the soil. 



We did learn, however, why fall cultivation will destroy the 

 wireworms ready to pupate, the pupae, and the beetles ; the beetles 

 can also be trapped and killed in large numbers with poisoned 

 clover baits. We also learned that many commonly recommended 

 plans are useless. 



Such a short rotation of crops as will include a period of thorough 

 cultivation in the fall will prove the best method of fighting these 

 pests yet suggested. * 



IV. Notes on the Transformations of Several Species of 



Wireworms. 



We used nearly 10,000 wireworms in our experiments. They 

 were collected by correspondents in Lewis county and forwarded to 



