292 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



least something definite to work on. On the other hand, if the fly is 

 found to breed in equal numbers in the different varieties there is 

 still the possibility that some of the varieties will be able to resist the 

 effects of the fly better than others. 



Studies are being made to determine whether or not plwsiological 

 differences in plants of the different varieties, chemical composition 

 of the sap, ash content and other factors associated with the plant 

 itself, tend to make plants of one variety more attractive to the fly. 

 Such factors as stooling, hardiness of plants and strength of stalk, 

 which may tend to help the plant resist the work of the pest, are also 

 being investigated. In the end the subject of yield must be con- 

 sidered. Much valuable data on comparative yields of the standard 

 varieties, in different sections of the state both for fly-years and fly- 

 free years are available from the records of the Department of Farm 

 Crops, but additional records will be secured from carefully laid out 

 plots where the factor of fly injury alone will be considered. 



Result of First Year's Work. — In the first year's work only 

 three varieties of wheat were used: Fultz, Fulcaster and a supposed 

 fly-immune variety developed by a farmer. The plots were sown side 

 by side the 24th of October, 1914. The soil was rich and had stood 

 idle the previous summer. The plot was a quarter of a mile from the 

 nearest wheat and a mile from badly infested wheat. The late date of 

 sowing, together with the distance from infested wheat, prevented 

 the fly from appearing in it in the fall. In order to make sure that some 

 fly would be present in it in the spring, infested volunteer wheat was 

 collected and evenly distributed in small piles about the plots on 

 April 10, 1915. Two days later flies were found on the wheat and the 

 plots became severely infested. 



On May 1, maggots were found to be abundant in all three of the 

 plots and on May 3 the first flax-seed stages were found. On May 

 10, samples of wheat were collected at random from the three plots 

 and counts made to determine the number of larvae and "flaxseeds" 

 present. From these counts the following data was secured: 



Variety Per Cent of Greatest Number Average Number 



Stools Infested in a Single Stool per Stool 



Fultz 58 18 2.72 



Fulcaster 66 8 1 .46 



Check 54 12 1.7 



In Fulcaster the infestation was more general, though decidedly 

 lighter than in the other two varieties. Fultz was decidedly the most 

 heavily infested which agrees with the observations of practical 

 farmers. The check or supposed immune variety was slightly more 

 heavily infested than Fulcaster. 



