468 Journal of Agricultural Research voi. xvm, no. 9 



Table IV. — Results of transferring larvcs of Oscinis frit from young wheat stems to young 



oat sterna 



Larva 



No. 



176 

 177 

 178 

 179 

 180 

 186 

 187 

 188 

 189 

 190 

 199 



2CX> 

 201 

 202 



203 



204 



205 

 206 

 207 

 208 

 209 



210 

 211 

 212 

 213 

 214 

 216 

 217 

 218 



Died without entering oat stem. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Refused to enter oat stem, and after 7 days the nearly starved larva was placed 

 in a vial with a wheat stem, which it entered and in due time emerged as a 

 normal adult, Oct. 15. 

 Refused to enter oat stem, and after 10 days the nearly starved larva was 

 placed in a vial with a wheat stem; it was however too weak to enter, and 

 soon died. 

 Entered oat stem and fed; pupated normally; its emergence was not noted 



in the record. 

 Died without entering oat stem. 



Do. 



Do. 

 Entered and fed normally, and adult emerged Oct. 15. 

 Entered and fed, but left stem to wander on glass; however pupated and 



emerged Oct. 14. 

 Died without entering oat stem. 



Do. 

 Entered and fed, but died without pupating. 

 Died without entering oat stem. 



Do. 

 Larva was nearly full-grown and pupated without entering oat stem. 

 Died without entering oat stem. 

 Larva was nearly full-grown, and pupated apparently without feeding. 



Thus it appears, disregarding larvae 216 and 218, that out of 27 larvae 

 transferred, only 4 (204, 208, 209, and 212) accepted the oat as a food 

 plant, and i of these did not reach pupation; 2 of the 4, however, 

 emerged as adults and showed no differences from specimens reared 

 entirely upon wheat. 



A control series on the same dates, in which larvae were dissected 

 out of wheat stems and placed in vials on other wheat stems, gave the 

 results recorded in Table V. 



Of the 13 larvae transferred in this test, only 3 died without entering 

 the wheat stem, 7 went through their transformations normally, while 

 the failure to get an emergence record for the remaining 3 probably is 

 not due to the transfer. It may be presumed that in both series some 

 larvae suffered unnoticed injuries while they were being removed from 

 the stems. The net result of the two series shows that larvae of the Ameri- 

 can species, when they have once begun to feed in wheat, are very loath 



