196 Journal of Agricultural Reserach voi.xxn. no. 4 



In June, 19 18, two pairs of adults from oak were caged on a collection 

 of oak, hickory, ash, maple, and chestnut logs, all cut April 15, and of 

 about equal size. Examination in July showed that the oak was heavily 

 infested (over 50 larvae present), the chestnut contained 10 larvae, the 

 hickory 7 larvae, and the ash and the maple none. 



At the same time a similar cage was prepared, and six pairs of adults 

 were placed in it to test the influence of a greater number of beetles 

 on the selection of hosts. The results showed the same relative propor- 

 tion of infestation except that ash also was attacked. The maple was 

 not infested. 



In June, 1919, this experiment was repeated with the same conditions 

 except that the hickory sticks were accidentally omitted. They were 

 examined in July and the infestation was as follows : The woods in the cage 

 of two pairs of adults contained 28 larvae in oak, 22 in chestnut, and none 

 in ash and maple; that of six pairs contained over 50 in oak, 19 in chest- 

 nut, and none in ash or maple. 



HicoRiA. Experiment I ^ — May, 1915, hickory logs were placed (as 

 before described) in the oak cage with the wood intended to carry on 

 the colony. They were infested and in subsequent years kept isolated 

 and continued as the hickory form. 



In June, 191 6, oak was placed in this cage, together with the hickory 

 to continue the colony, and was subsequently found heavily infested. 



In June, 19 17, together with the hickory for reinfestation, chestnut 

 and locust were placed in the cage. An examination in July showed 

 that the chestnut contained a few larvae and the locust none. 



In June, 1918, two pairs of adults were isolated in a cage containing 

 oak, hickory, ash, chestnut, and maple, all cut April 15, and of equal 

 size. The results showed that the hickory was heavily infested by over 

 50 larvae, the oak contained 7 larvae, the chestnut i larva, and the maple 

 and ash none. 



In June, 19 19, selection tests and selection quantity tests were carried 

 out with this strain. The quantities and cuts of wood were the same 

 as before, except that oak was accidentally omitted. In one cage two 

 pairs of adults were isolated, the resulting infestation being hickory 

 18 larvae, chestnut 12 larvae, maple and ash none. In another cage six 

 pairs of adults were isolated, the resulting infestation being hickory over 

 50, chestnut 40, and maple and ash none, 



Castanea. Experiment I ^. — In May, 1916, chestnut logs were placed 

 (as before described) in the oak cage with the wood intended to carry on 

 the colony. The wood was heavily infested, and these individuals have 

 since been confined to chestnut. 



In May, 191 7, together with the chestnut, hickory was placed in this 

 cage. The hickory was lightly infested. 



In June, 19 18, two pairs of adults were isolated in a cage containing 

 oak, hickory, ash, chestnut, and maple, all cut April 15 and of equal 



