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PROTECTION OF PLANTS, 1915-16 



Wheat Stem Maggot or Wheat Bulb Worm. 



This insect produces a form of the well known "silver top" or "white- 

 head" disease of wheat, rye and barley, timothy and other grasses. There 

 are probably three broods in a year, the adults appearing in May, July and 

 September. It winters as a maggot in the young plants. 



This insect is difficult to control. The following measures have been 

 found of value: (a) grain stacked or threshed and the straw stacked^or 

 burned; (b) burning of the stubble. 



Wheat Midge (Diplosis tritici) — -a, female fly; 6, male fly; c, ventral view of larva. 

 (After Marlatt). 





Wheat bulb-worm (Meromyza americana) — a, mature fly; b, larva; c, puparium; d, infested wheat 

 stem — all enlarged except d. (After Marlatt). 



