30 NEW YORK STATE MUSEUM 
sprayed twice and those sprayed once, accompanied by an increase 
of 562 side wormy apples; in other words, each apple worm suc- 
cessfully evading the first spray appears to have produced approxt- 
mately 5.6 side wormy fruit later. Similarly, a difference of 217 
end wormy and 1963 side wormy will be noted between plots 
sprayed three times and those sprayed once, there being a ratio of 
I to g between the increase of end and side wormy. Now, if we 
bear in mind the importance of the first ‘application in reducing the 
end wormy (this comprises about two-thirds of the total wormy 
fruit on unsprayed trees) from 20.95 to .349 or .353 per cent (the 
former an average of three years’ work with one spray, the latter 
the return from four years’ work), we can hardly escape the con- 
clusion that the very best way of controlling the second brood 1s to 
spray most thoroughly for the first. Some six years ago Professor 
Ball of Utah estimated that under conditions obtaining in that state, 
two sprayings during the first period mentioned above, namely, 
within a week or ten days after the blossoms fall, are worth six to 
sixteen times as much as three late ones. This ratio is approxi- 
mately true for our conditions, though considerable variation may 
be expected from year to year. Checks in the fruit from hail 
storms, sun scald, or burning by insecticides or fungicides afford 
easy and safe points of entrance for second brood larvae and have 
a material bearing upon the production of sound fruit. All having 
practical experience with this pest know only too well how quickly 
the young apple worms take advantage of these opportunities. The 
development of such conditions as those just mentioned or the 
somewhat common occurrence of wormy apples in early July would 
be ample justification for a treatment the latter part of that month 
or early in August for the purpose of destroying second brood 
apple worms before they can enter the fruit. 
Conclusions. A study of the data collected during the past four 
years justifies the conclusion for the Hudson valley at least, that in 
normal seasons when the crop is abundant or fairly abundant, one 
thorough early spraying within a week or ten days after the blos- 
soms fall and preferably early during that period, should result in 
the production of 95 to 98 per cent of sound fruit. A slight gain 
will accrue from a second treatment about three weeks later, and 
additional returns may be secured from a third spraying the latter 
part of July. The benefit from the latter two is comparatively small, 
so far as the codling moth is concerned, though ample to meet the 
cost of the poison and, in many instances, probably the expense of 
