I902 The Cornell Reading-Courses 



this time it can be sprayed into the calyx cup most easily. This is the 

 most important spray for the codling moth and should be applied with 

 great thoroughness. The material now almost always employed against 

 the codling moth is arsenate of lead. It may be used either in the paste 

 form or in the dry, or powdered, form. From four to six pounds of the 

 paste or from two to three pounds of the powder should be mixed with one 

 hundred gallons of water. It is necessary that the spray be applied with 

 a pump giving a pressure of from one hundred to two hundred pounds 

 per square inch, and the spray should be directed downward so as to hit 

 the young fruits squarely in the blossom end. In order to do satisfactory 

 work on the higher branches, the man handling the nozzle should stand 

 on an elevated tower high enough so that with an extension rod twelve or 

 fourteen feet long he can reach out over the top of the tree and by means 

 of an angle nozzle direct the spray downward into the ends of the young 

 apples. In the case of very tall trees it is impossible to thoroughly spray 

 the tops; and under such circimistances it is better to head in the trees 

 by judicious pruning. By doing very thorough work with this first spray 

 it is possible to produce a crop of apples from ninety-five to ninety-eight 

 per cent free from codling moth injury without making any later applica- 

 tions of the poison. 



As has already been stated, the codling moths do not begin to emerge 

 until about a week after the petals fall, and the eggs do not begin to hatch 

 until about two weeks later, or three weeks after the petals fall. If an 

 additional poison spray is applied at the time when the young caterpillars 

 are hatching, many of them wiU be poisoned by feeding on the foliage 

 before reaching the apples, since a large proportion of the eggs are laid 

 on the leaves at some distance from the fruit. The spra}^ will also coat 

 the surface of the young fruits with, poison, and thus kill many of the 

 caterpillars that attempt to enter at the side. While this application is 

 not absolutely necessary for the control of the codling moth, nevertheless 

 a spray is usually applied about this time for the control of apple scab, 

 and it will do enough good to more than pay for the arsenate of lead used, 

 which is the only additional expense involved. 



The best way to control the second brood of codling moths is to do 

 such thorough and careful work in spraying for the first brood that prac- 

 tically no caterpillars will survive to give rise to moths of the second 

 generation. In case, however, a person has been unsuccessful with the 

 earlier applications of the poison, it is sometimes advisable to spray for 

 the second brood about the first of August. As has been stated, the size 

 and the importance of this second brood depend on the earliness of the 

 first brood, and this in turn depends on the temperature during May and 

 June, When the season has been early, there is more danger that the 



