232 CROP PRODUCTION 



several weeks. Then they pupate at or just beneath the 

 soil surface, to emerge a httle later as beetles. Plowing 

 the crop under in May or June is an effective remedy, as 

 it destroys the larvae. 



If you take a dozen clover blossom heads, especially 

 such as show a green and dwarfed condition, and shake 

 them violently over a sheet of paper you may often dis- 

 lodge tiny orange colored maggots, about one tenth of 

 an inch long. These are the larvae of the Clover-seed 

 Midge, an insect that often greatly reduces the crop of 

 clover seed. The adult is a small two-winged gnat, with 

 a long ovipositor by means of which it inserts eggs into 

 the young florets of the red clover head. From these 

 eggs the orange colored larvae hatch and develop at 

 the expense of the embryo seeds. When full grown the 

 larvae wriggle their way out of the head and fall to the 

 ground, where they form shght silken cocoons within 

 which they change to pupae. About ten days later 

 they change again to the gnat-like flies that lay eggs for 

 another brood of larvae. 



The injuries of the Clover-seed Midge are especially 

 serious only in case the crop is grown for seed. Infested 

 fields are distinguished by the green and dwarfed condi- 

 tion of the heads at blossoming time. The best prevent- 

 ive seems to be that of mowing the field in spring when 

 the green heads are forming. There is thus produced a 

 crop of blossoms which escape attack. 



