The More Important Apple Insects. 87 
spray schedules to control all of the troubles of the apple, a very large pro- 
portion of those controllable by sprays ean be kept down by the use of the 
spray-schedule plan. In the subsequent pages schedules are presented cov- 
ering the principal orchard districts of the country, which may be modified in 
accordance with the needs of individual 
orchardists. In this connection, it 
should be borne in mind that the rela- 
tive abundance of pests varies from year 
to year as influenced by weather and 
other conditions. The apple grower 
should therefore be constantly on the 
alert and prepared to cope with any 
unusual conditions that may arise from 
time to time. If the fruit grower is not 
well acquainted with his insect and fun- 
a Fic, 180.—Proper stage at which to 
gous troubles, he will do well to consult begin Roe analcetion: 
the State agricultural experiment sta- 
tion, the United States Department of Agriculture, or some other competent 
agency interested in the suppression of orchard pests. 
THE CALYX SPRAY. 
The so-called ‘“ calyx spray” or ‘“ petals-off’’ application is generally recog- 
nized as the most important spray for the apple during the growing season and 
is particularly valuable against the codling moth. The primary object of this 
application is to fill each calyx cup with poison in order to kill the worms that 
attempt to enter the fruit through the calyx or blossom end. The time within 
which this spray ean be effectively applied is limited and every effort should 
be made to do the work within the prescribed period. The spraying should be 
begun as soon as the petals have dropped (fig. 180) and should be completed 
before the calyx cups have closed (fig. 
181). As an insurance in covering the 
orchard in time it is often desirable to be- 
gin the spraying when 85 to 90 per cent 
of the petals have dropped, but care should 
be taken not to spray earlier on account of 
possible injury to the honeybees. 
It is well known that certain varieties 
of apples bloom earlier than others and 
that with each variety there is more or 
less variation in the development of the 
bloom. The orchardist should therefore 
carefully inspect the blossoms and time 
the spraying with reference to those most 
advanced. Under ordinary circumstances 
the center blossom is the most advanced 
Fic. 181,—Too a to make calyx aP- 4nd the most likely to set fruit. 
Peeee ke The development of the calyx cup of 
the Baldwin from the time the petals fall until the cup has closed is shown by 
means of the vertical sections in figures 182, 183, 184, and 185. In figure 182, 
which represents the cup just after the dropping of the petals, it will be noted 
that the sepals are about at right angles to the flowering parts and form a bread, 
shallow cup which can be readily coated with the poison spray. Six days later, 
