the rule. Then if the data gathered is sufficient to explain the entire 

 occurrence of the insect for the year, we have no occasion to introduce 

 partial broods. In fact I think their existence should only be 

 announced upon the most positive evidence. 



While the data that I have to offer in this address bear chiefly upon 

 the matter of broods of the codling moth, I have not confined myself 

 to that feature of its life history, and shall give such records and 

 observations as I think maj^ be of interest from our studies of this 

 insect. 



SPRING BROOD OF LARV^ AND PUP^.. 



In our early spring studies of this insect we have always found it as 

 a larva in all portions of Colorado. It begins to pupate freely just 

 prior to the blooming of the apple trees, at which time, also, the earliest 

 moths ma}^ be taken. The date of pupation varies greatly. Those 

 upon the south side of trees pupate earlier than those upon the north, 

 wliile others going into the earth about the base of the tree (which many 

 do) or deep into some checked trunk or rotten stump change still 

 later. The time spent in the pupa state by this brood has varied with 

 us from 13 to 68 days, and the time has been as long in the Grand 

 Valley as at Fort Collins. 



April 23 of the present j^ear the writer took 285 larvae and 7 pupae 

 of the codling moth under bands in an orchard at Fort Collins. May 

 10^ when the early trees were in bloom, he took 33 larvae and 4 pupae. 

 From the latter date pupation took place much more rapidly. 



SPRING MIGRATIONS OF THE LARV^. 



I think it was in the spring of 1899 that I was told that a man living 

 near Grand Junction had put bands upon his apple trees in February, 

 and taken many larvae of the codling moth under them. The follow- 

 ing spring I requested parties in Rockyford, Grand Junction, Canon 

 City, EdgCAvater, and Fort Collins to place at least 10 bands upon trees 

 early in spring, to be examined weekly and report results. From 

 all these bands but 6 larvae were taken. The past spring I was in 

 Grand Junction when Mr. Silmon Smith was removing bands to catch 

 the migrating larvae (May 8), and he reported 53 worms from 295 

 bands remaining on two weeks. I also addressed a letter to Mr. 

 W. H. Barber, of Grand Junction, who it was said had been very 

 successful in taking the larvae, and he reported taking 307 larvae 

 April 2 and 409 April 17 from 2,500 bands. So there is a small per- 

 centage of the larvae that seek a new place for pupation in the spring, 

 but the number is usually so small that it seems doubtful if it will 

 often be a matter of economy to attempt to capture them under bands. 

 I can not vouch for the identification of larvae in the last instance, but 

 if they were all of the codling moth, working the bands must have 

 paid well. 



