9 
the rule. Then if the data gathered is sufficient toexplain 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 codiing moth, I have not confined myself 
to that feature of its life history, and shall give such records and 
observations as I think may be of interest from our studies of this 
insect. 
SPRING: BROOD OF LARVZ 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 may be taken. The date of pupation varies greatly. Those 
upon the south side of trees pupate earlier than those upon the north, 
while 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 inthe pupa state by this brood has varied with 
us from 15 to 68 days, and the time has been as long in the Grand 
Valley as at Fort Collins. 
April 25 of the present year the writer took 285 larve and 7 pup 
of the codling moth under bands in an orchard at Fort Collins. May 
10, when the early trees were in bloom, he took 33 larvee and 4 pupe. 
From the latter date pupation took place much more rapidly. 
SPRING MIGRATIONS OF THE LARVZ. 
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 larvee of the-codling moth under them. The follow- 
ing spring I requested parties in Rockyford, Grand Junction, Canon 
City, Edgewater, 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 larve were taken. The past spring I was in 
Grand Junction when Mr. Silmon Smith was removing bands to cateh 
the migrating larvee (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 larve, and he reported taking 307 larvee 
April 2 and 409 April 17 from 2,500 bands. So there is a small per- 
centage. of the larve 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 larve in the last instance, but 
if they were all of the codling moth, working the bands must have 
paid well. , 
