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ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



This paper was followed by a general discussion, which was par- 

 ticipated in by Messrs. Titus, Fletcher, Hopkins, Bishopp, Kirkland, 

 and others. It proved to be of exceeding interest to all present and 

 served to show the value of thorough and careful investigation of 

 problems which are not given the attention they deserve. 



Mr. Webster added two interesting facts relative to Isosoma tritici. 

 In the past it had always been thought necessary, as a precautionary 

 measure, to burn the infested bits of hardened straw that break up 

 in thrashing the wheat, many being carried out with the grain instead 

 of going over in the straw. Several experiments in rearing adults 

 from large numbers of these broken bits of straw, collected about 

 elevators and threshing machines, has shown that almost all of the 



larvae of both Isosoma and 

 parasites are killed, prob- 

 ably by the concussion of 

 the cylinder of the thresher. 

 In some cases we have been 

 able to verify these experi- 

 ments by collections of stub- 

 ble from fields in the vicin- 

 ity of these elevators. So 

 far as we have gone into 

 the investigation everything 

 indicates that the danger 

 from these broken bits of 

 hardened straw, or even the 

 straw itself, is of too little 

 importance to be worth con- 

 sideration. Prof. R. H. 

 Pettit, of Agricultural Col- 

 lege, Mich., and also one of 

 Mr. Webster's own assist- 

 ants, Mr. W. J. Phillips, in 

 northern Indiana, have this year (1906) found great numbers of 

 straws affected by the jointworm, where the enveloping sheath has 

 been torn away and the galls formed by the larvae deftly eaten away 

 and the jointworms missing. In no case is the entire gall gnawed 

 away, but just enough of the walls immediately over the larva to 

 make possible the removal of the latter (fig. 5). While we have not 

 been able to get definite information as to the identity of this 

 decidedly beneficial animal, suspicion seems to point to the short-tail 

 shrew (Blarina brevicauda) as the species to which credit should be 

 given, and probably much of the work is done while the grain is in 

 shock. 





Fig. 5. — Wheat straws injured by the jointworm 

 (Isosoma tritici) from which the jointworms 

 have been removed by some beneficial animal, 

 perhaps the short-tail shrew (Blarina brevi- 

 cauda), (Original.) 



