12 The Bulletin. 



The following account will give a general idea of the history of those 

 species that attack corn, the details probably varying somewhat in the 

 different species : 



Many of the adult beetles pass the winter in dead wood, under bark, 

 under trash, boards, leaves, at the base of tufts of grass, etc. In the 

 summer they lay eggs, usually depositing them in grassy places. The 

 larvas hatching from the eggs are slender, smooth, yellowish-brown in 

 color and firm in texture, and are called "Wire- worms." They burrow 

 through the soil, feeding on various seeds and roots which they may find. 

 It is thought that it takes most species from two to three years to reach 

 maturity. Then they change to the stage known as the 'pupa in a cell in 

 the soil. While in the pupa state they are quiet and take no food, bvit 

 are going through the change from larvae to adult beetles. After a few 

 weeks in the pupa state the insect changes to an adult beetle. Some of 

 the beetles emerge and pass the following winter in sheltered places; 

 others do not emerge until the following spring. 



Summary. — It will be noticed from the foregoing account that Wire- 

 worms are more destructive on lowlands, and that they are worse on 

 lands which have been in sod. Thev feed on seeds, roots, and stems. 

 It is probable that they do not attack corn or other cultivated crops be- 

 cause they especially like them, but because when sod lands are broken 

 up they are already in the soil, their natural food is destroyed, and they 

 must take what is planted. It takes from two to three years for a gen- 

 eration to reach complete maturity, and adults deposit eggs mainly in 

 sod lands. With these facts in mind, we can better appreciate the recom- 

 mendations which follow. 



KEMEDIES. 



The first consideration in attempting to avoid injury to corn by Wire- 

 worms is not to allow corn to follow directly after sod. If corn must 

 follow sod, plow the land in the fall and stir once or twice during the 

 winter. These measures will starve and kill by exposure many of the 

 larvae and will break open the little cells in which the newly formed 

 adults are passing the winter and kill the insects. By avoiding low 

 lands (especially low sod lands) much injury will be averted. Good 

 fertilization and frequent tillage will also check the insects or enable the 

 corn better to recover from their attacks. 



In regard to corn after sod, it should be remembered that most species 

 of Wire-worms are thought to take two or three years to become full- 

 grown, hence it is well to have the land in some other crop not so sub- 

 ject to injury during the first year from sod, so that the majority of the 

 insects will have had time to mature and deposit their eggs elsewhere. 



But Dr. Forbes in Illinois states that they "are much more likely to 

 do serious mischief the second year after the breaking up of the sod," 

 which would indicate that in severely infested fields it would be better 



