60 JOURNAL OF ECONOMIC ENTOMOLOGY ' [Vol. 14 



effort of the growers. The damage from the late wave of October 

 flies is considerable, but insignificant when compared with the result 

 of the visitation of the main fall brood of 1919, the like of which the 

 farmers of Ohio missed in 1920 by pulling all together. 



Summary 



Summarizing the Ohio work we believe we are justified in claiming: 



First, that an annual entomological wheat survey just before harvest, 

 such as Ohio has maintained for four seasons, will reveal an approaching 

 outbreak of Hessian fly and prevent surprise. 



Second, that several fly emergence stations located at selected points 

 over the state will furnish the most dependable data obtainable upon 

 which to base recommendations for safe seeding dates for the different 

 localities. If some or all of the emergence stations fail to yield decisive 

 results, the sowing dates established bv plot tests through a series of 

 years should be used to guide the sower. 



Third, that a well organized extension service cooperating with the 

 count}' farm bureaus can get the recommended dates for seeding into 

 the hands of the farmers within 24 hours or less after they are deter- 

 mined from the emergence records. And, futher, that by energetic 

 preliminary work the Extension Entomologist can secure the ready 

 cooperation of 99 percent, of the farmers in a seeding campaign. 



Fourth, that as a result of our annual surveys and correlated efforts, 

 a threatened heavy brood of fly has been kept suppressed, and that there 

 will be twice as many bushels of wheat in Ohio in 1921 as would have been 

 the case, had we given the insect no attention. 



Mr. W. p. Flint : The experiences stated in this paper are about the 

 same as those we have had in Illinois this year, particularly concerning 

 the great variation in the actual fly-free dates. From 1918 to 1920, the 

 dates varied 22 days at Champaign, 111. 



Mr. J. J. Davis: M}^ recent observations in southern Indiana indi- 

 cate that the late wave of fly is still in the larval stage and very likely 

 these larvae will not mature and not issue next spring. 



Mr. T. H. Parks: The change from the larva to the flaxseed stage 

 in Ohio has been very recent. Three weeks ago there were very few^ in 

 the flaxseed stage in southern Ohio, but now over half of them are in 

 that stage. 



Mr. H. a. Gossard: Three-fourths of them are in that stage in 

 northern Ohio. 



President Wilmon Newell: The next paper entitled "The Potato 

 Leafhopper and Tarnished Plant Bug in 1916," will be presented by Mr. 

 S. Marcovitch. 



