BENEFICIAL INSECTS, PREDACEOUS AND PARASITIC 21 



distributed, and there can be no question that before long we 

 shall come to better understand how we may make use of these 

 valuable allies, and some day we may be able to duplicate the 

 apparent miracle by which Dame Nature sweeps away an insect 

 plague in a few days with the aid of these apparently insignificant 

 parasites. 



