304 BEES AND WASPS 



is an excellent plan to reduce the infestation. Of course 

 burning chaff or straw would accomplish the purpose, but 



Fig. 247. — Isosoma trilici: adult male. (Photo by Ohio Exp. Sta.) 



Fig. 248. — Isosoina tritici: larvae. (Photo by Ohio Exp. Sta.) 



this is not deemed necessary if the straw passes through the 

 barnyard, as most of the pupa? are killed by this treatment. 



