April, ’20] 
HEADLEE: CODLING MOTH 
171 
brood. All studies agree in placing the time for the first spraying for 
codling moth at the falling of the blossoms. Taking the great mass of 
codling moth study in general and accepting the work of the men 
mentioned, the writer believes that the consensus of opinion would 
place the spraying which is intended to protect the fruit from the side- 
worms of the first brood about three weeks after the blossoms fall and 
would place the spray which is intended to protect the fruit from the 
side worms of the second brood about nine weeks after the blossoms 
fall. 
A study made of the blooming period for Gravenstein, Baldwin, 
Williams and Ben Davis, extending from the year 1908 to the year 
1918 shows an extreme variation of about three weeks and an average 
variation of a trifle over a week. It is the writer’s understanding, 
drawn from different sources, that this variation is due primarily to 
temperature. Knowing the tremendous retarding effect of low tem¬ 
peratures and the large accelerating effect of higher temperatures, the 
writer is inclined to believe that the temperature factor would operate 
upon the codling moth in much the same way and to about the same 
extent as it does on the tree. He is, therefore, inclined to think that 
the interval existing between the blossom fall and the larval entrance 
into the fruit is not so variable as has hitherto been shown. Without 
doubt factors of moisture seem to influence the codling moth pupa 
somewhat differently from the way in which they influence the bloom¬ 
ing period of the tree and variations due to that cause may very well 
take place, but the amount of variations resultant is not likely to be 
large enough materially to change the relationship between the time of 
bloom and the time of larval entrance. 
The facts above set forth seem to leave the question of the method of 
indicating the time of the spray for control of the first brood of side 
worms unsettled. It may be said that Quaintance has obtained excel¬ 
lent results from the day and month date method and that equally 
good results have been obtained by following a schedule based on the 
blossom period. The underlying factors do not seem to have been 
worked out and further investigations will, in the writer’s opinion, 
bring them forth. 
Explanation of Charts 1 and 2 
Chart 1 showing the emergence of broods of moths and the period covered 
by the entrance of their larvse into the apples in 1919, at Maple Shade near 
Camden, N. J. 
Chart 2 showing the blooming period of four varieties of apples from 1908 
to 1918 inclusive. Extreme variation is about three weeks and average about one 
and one half weeks. 
