84 Agricultural Experiment Station, Ithaca, N. Y. 



November 1st, and hibernate until spring. AVlien the worms are 

 fullj' grown thej change to soft white pupa3 which resemble the 

 beetle in form. This change takes place in the species that com- 

 monly infests field crops during the month of July. The pupa 

 state lasts only about three weeks, the insect assuming the adult 

 form in August, But, strange to say, although the adult state is 

 reached at this time, the insect remains in the cell in the ground 

 in which it has undergone its transformations till the following- 

 April or May, nearly an entire year. 



We found that in every case where we disturbed the soil so as 

 to break these earthen cells, the insects within penshed. 



This experience clearly indicates that if infested fields are 

 plowed after July 20th and thoroughly pulverized and kept stirred 

 up, many of the little earthen cells may be broken and the tender 

 pupae or beetles within destroyed. After three or four weeks of 

 this thorough cultivation, wheat or rye may be sown. 



In connection with this fall plowing and cultivation we earnestly 

 recommend the method of short rotation of crops to farmers hav- 

 ing land badly infested with wireworms. Do not keep fields in 

 sod for more than a year or two at a time. No doubt it will require 

 several, at least three years by this method, to render the soil com- 

 paratively free .from the pests as only the pupse and adults are 

 killed each fall, while most of the one and two-year-old wii'eworms 

 will escape injury. Those farmers who practice the method are not 

 troubled with wireworms. 



2. Trapi'ing. 



Our experiments on preventing the ravages of wireworms by 

 trapi)ing were carried on in 1888 and 1889, Two methods were 

 employed, trapping by baits, and by lanterns. 



On trapping hy halts. — This method has been discussed in detail 

 in Bulletins 3 and 33 of this Station, so that only the general results 

 will be given here. The baits, which consisted of sliced potatoes, 

 wads of green clover, and sweetened and unsweetened cornmeal 

 dough were placed under boards in various parts of a badly in- 

 fested corn field. Instead of attracting the wireworms, as was 

 expected, their parents — the click-beetles — came to the baits in 

 large numbers ; the clover attracted by far the larger number (65 

 per cent). 



