April, '16] HASEMAN: HESSIAN FLY 293 



A second set of samples were collected on June 18, which gave the 

 following data : 



Variety No. of Maggots Flax- Parasit- Emerged 



Stools seeds ized 



Fultz 100 92 69 12 3 



Fulcaster 100 11 23 4 6 



Check 100 21 3 



Here again Fultz showed a decidedly heavier yield of maggots and 

 "flaxseeds" while the check variety showed fewer than Fulcaster. 

 In all three of the varieties there was a smaller total number of mag- 

 gots and "flaxseeds" than on May 10. Some had emerged to form a 

 partial second spring brood and the wheat was all badly lodged which 

 with the excessive rainfall made it difficult to collect all the "flaxseeds" 

 when the samples were gathered. 



From this data it seems unquestionable that some varieties become 

 more severely attacked by the fly than do other varieties. Fulcaster 

 shows decided tendencies toward immunity as compared with Fultz 

 in this test at least. This data also show that a supposed highly 

 immune variety may in reality be as badly attacked as some of our 

 standard varieties. 



In connection with the studies on the stooling properties of the 

 three varieties under consideration, counts were made on June 26. 

 From these counts the following data were secured: 



Variety Average Number of Stools per 



Plant 



Fultz 4.39 



Fulcaster 3.71 



Check 3.67 



In this particular experiment Fultz which was the most severely 

 infested showed a slight increase of stools, though not enough to 

 counter-balance the greater supplj' of flies which it was called on to 

 feed. 



Lodging. — Observations on the tendencies of the three varieties to 

 lodge showed that there was little difference between Fultz and Ful- 

 caster but the check variety practically all lodged. In all of the varie- 

 ties lodging was very severe as would naturally be expected from the 

 extent of infestations. 



Ash Content of Plants and Straw. — ^Determinations of the ash 

 content of the different varieties have been made to see if it varies 

 materially in the three varieties and also if it perhaps may be a factor 

 in attracting or repelling the fly. Analyses have been made of young 

 wheat plants taken when the fall brood of maggots were at work; also 

 of the mature straw. These analyses do not show any very material 



