ORDER HYMENOPTERA 



303 



straw. Sometimes the hard pieces of straw are carried over 

 in tile threshing and mixed with the grain. It is evident 



Fig. 21(). — Iso^oma trilid: female ovipositing. (Photo by Ohio Exi). Sta.) 



that burning of the stulible in the fall or early spring will 

 destroy the pupa in the fields and it is considered that the 

 use of straw and cliaif in the bedding of stock or as fodder 



