Of "remedial and preventive measures," that is, artificial 

 means of control, the Bureau recommends in the case of Tip- 

 ula infuscata, "to plow infested sod under in the early fall, and 

 either run the fields into corn, potatoes and such crops, or to 

 leave the land fallow the ensuing summer. Pastures and hay- 

 fields, in localities where this species is known to be abundant, 

 should be grazed off by the middle of September, and kept so 

 until late in November, as the adult flies usually congregate in 

 rank growth of grass, clover, weeds, etc., and there lay their 

 eggs" (p. 131). 



Thus you have at least one case where the Bureau finds 

 it handy to have some rank growth outside of fields and pas- 

 tures growth on waste land as they call it to serve as ovi- 

 position ground, anyway up to late in November. With the 

 pastures and hayfields kept thus grazed not many insects of 

 any kind will stay there good, bad or neutral nor will max- 

 imum yieds be thus secured or will these pastures and hay- 

 fields winter as well or hold water and snow as well as if a 

 heavier growth had been left on in the fall. Besides in the 

 case of the earlier kind this does does not work at all. Most 

 species emerge from March on to past mid-summer and thus 

 lay their eggs where they see fit, live as larvae during summer, 

 pupate and emerge during the first part of the next season. 

 In other words, the Bureau has no remedy for these species at 

 all. 



There is, however, a perfectly satisfactory remedy, a remedy 

 evolved along the line of the U. S. Entomologist's pet hobby 

 the use of natural enemies in the control of injurious insects 



15 



