10 THE WHEAT- STEM MAGGOT. 



steps are taken to prevent it a repetition may become ruin- 

 ously large in 1893." 



Most farmers plowed their fields during the fall of 1892 

 or early in 1893, and consequently the losses in the latter 

 year were small, and in 1894 but very few of these insects 

 could be found. The spring of this year, being very w^et, 

 prevented extensive plo\ving, and the insects not being dis- 

 turbed or plowed under again became a pest and caused 

 considerable damage. The name "Frit-fly" is a well de- 

 served one, as the Swedish farmers call the worthless grain 

 resulting from the attacks of such flies: "frits." 



The life-history of this insect is still very obscure in 

 many points and careful work is required to learn it. 



THE WHEAT-STEM MAGGOT. 

 {Meromyza amerlcana Fitch). 



This insect (plate XIV) has again been destructive in 

 many parts of Minnesota, and it threatens to become in the 

 future a serious enemy to our crops of small grains. In 

 some parts of the state the late sown rj'^e, which had made 

 but little growth during the autumn and which grew slowly 

 in spring, w^as greatly damaged, in some cases to the extent 

 of one-tenth of the crop. Wheat did not entirely escape, 

 and the plants infested by the insects showed their presence 

 by their small size and general weakly appearance. An ac- 

 count of the life-history of this insect was given in last year's 

 report, so it is not necessary to discuss now its habits in de- 

 tail. Many points in this life-history are still obscure; as 

 yet we do not even know how this insect passes the winter 

 in Minnesota, oi" where. In 1896 it could be found in many 

 regions of the state, and the prominent white "bald heads" 

 were not difficult to find. Large numbers of the infested 

 stalks, especiall3'- those of rye, were kept in proper vessels to 

 see whether parasites were numerous enough to promise 

 assistance in the near future. But few were discovered, 

 however, and thus far the only remedy we have is a syste- 

 matic rotation of crops. 



