aT Is TAN. 
The More Important Apple Insects. 89 
as shown in figure 1838, the sepals have grown upward, making the cup some- 
what V-shaped. In figure 184, which represents the cup 8 days after the petals 
have dropped, the sepals have advanced further toward the closing point, form- 
ing a U-shaped cup. Spraying at this stage is still effective, since the cup is 
open sufficiently to admit the poison. Two days later, however, or a total of 
10 days after the petals have dropped, as shown in figure 185, the sepals have 
grown together and the cup is practically closed.. At this stage of development 
it is impossible to force the poison into the cup, and hence too late to apply the 
calyx spray. 
The rapidity of closing of the calyx cup varies somewhat with the variety 
and with the weather conditions. If the spraying is begun when 85 to 90 per 
cent of the blossoms have dropped, the time within which the calyx applica- 
tion should be made will usually cover a-period of a week to 10 days. The 
orchardist, however, should not depend upon the longer period, but, instead, 
should provide against unfavorable weather and other unforeseen interrup- 
tions by employing sufficient help and spray machines to complete the work 
within a week. 
