MONTANA EXPERIMENT STATION. 143 



NOTES ON THE BUD MOTH. 



By B. J. JONES.i 



This insect was discussed at considerable length in the Entomo- 

 logist's Report for 1903. Conditions were found to be so favorable 

 m the cage at Missoula, however, that it was thought best to make 

 a further critical study of it there during the summer of 1904. As 

 the work began May 12th and ended August 22nd this study of 

 course did not deal with the first spring activities or with the wirier 

 hibernation of the pest. The present publication may be regarded 

 as dealing with the seasonal dates and peculiarities of its transforma- 

 tion, and establishes, as we believe very conclusively, a number of 

 points in the life-history which difter considerably, in this state at 

 at least, from the ordinary routine as worked out and published in 

 the very excellent works of Professor Slingerland and others. As 

 these differences have much to do with the possible effectiveness of 

 insecticides they will be given special prominence m the present 

 discussion, while other points already established will not be con- 

 sidered. 



It was estimated that fully two-thirds of the flower buds on the 

 tree in the cage, from which all of the observations were taken 

 had been destroyed by the young larvae. Under date of May 12th 

 it was recorded that, though varying somewhat in size, the larvae 

 measured almost uniformly one-fourth inch in length. They were 

 rolled tightly in dead leaves, were practically inactive during the 

 day, and seemed quite invulnerable to any possible application of 

 spray. They were quite dark in color and apparently ready for the 

 first spring molt. Two days later this theory was verified, for a 

 number of larger, fresh larvae were found in the early morning mig- 

 rating from the former hibernacula and establishing themselves up- 

 on new and larger leaves. The migration soon became general and 

 a large per cent of the worms were found to move to other quarters 

 where they were for some time uncovered and susceptible to spray 



1. The work on the bud moth at Missoula in the summer of 1904 was con- 

 ducted by Mr. Burle J. Jones, a graduate from the Montana Agricultural Col- 

 lege in the class of 1904. The outline of the work that we desired do.ie was 

 given him and the special problems indicated. Mr. Jones is a conscientious 

 observer and promising student of economic entomology. 



