they visit, are much too small to fertilize more than a 

 small proportion of the flowers which produce seed. 



_Thri£s__ 



Thrips ( Enthri ps tritici ) were present in 

 large num"bers in the alfalfa flowers at Pullman, and in less 

 nmribers at Chinook, and Havre, Montana. At Pullman, 

 my thrills were found on 16 racemes of alfalfa flowers, 

 or an average of 69.9 thrips on the flowers of each 

 raceme. At Havre 48 thrips were found on 13 racemes. 

 Tl^ese minute insects do not trip the alfalfa flowers. 

 They were abundant on practically all of the plants used 

 in carrying out the experiments which have "been described 

 in this report. As only a very small percentage of the 

 flowers which were not at Pullma.n produced seed, and as 

 the flowers that were tripped produced seed abundantly, it 

 may be assumed that the thrips are neither apprecialoly 

 beneficial or injurious in their influence upon the 

 development of alfalfa seed. 



Mght -f lying Insects. 

 An experiment was conducted at Pullm_an in 1909, to 

 obtain information in regard to v;hether night-flying 

 insects are of any importance in fertilizing alfalfa 

 flowers. Seven plants were enclosed in fine meshed mosqu- 

 ito netting. Pive of these plants were left under the 

 netting during the entire time of the experiment in order 



(48) 



