APPLE GROWING IN CALIFORNIA. 81 



of a wrinkled or roughened appearance. The color at first is creamy 

 white. In a few days three or four a reddish ring may be plainly 

 seen within the shell. This rin_r marks the position of the embryonic 

 larva developing within. Before hatching, which normally takes place 

 about the seventh day, there may be seen a black spot near one side of 

 the egg. This spot is simply the black head of the little worm within 

 and indicates that hatchini: time has arrived. The thin white shells of 

 hatched eggs may cling to leaves or fruit for some time and can be seen 

 in any orchard where codling moth is at all bad, during the summer 

 season. 



Control. 



A very large per cent of the first brood larva begin feeding in the 

 <-alyx end of the apple, the number varying somewhat with seasons, 

 locality and variety, and estimated by scientific workers to be from 

 seventy-five to ninety-five per cent of the total brood. In the case of 

 the second brood quite a large percentage also enters the calyx, but as 

 the fruit is large when they come on there is a better chance for the 

 little worms to enter elsewhere, and quite a good many bore into the 

 fruit through the stem cavity or somewhere on the side. This fact, 

 coupled with the important one bearing on it, that sprays must be 

 applied to coat the entire surfaces of the apples, makes it of the utmost 

 importance to devote every energy toward killing practically the entire 

 first brood, so that the second as a consequence must be small. 



The fact that so great a percentage of the first brood of worms seeks 

 the calyx as soon as hatched has resulted in the standard method of 

 control for this pest, viz : a heavy spraying with some arsenical insecti- 

 cide when the petals are practically all off and before the calyx lobes 

 have dosed. 



Spray to Use. 



The most satisfactory and widely used arsenical spray for codling 

 moth is arsenate of lead. It is made in both the paste and powdered 

 form, the first mentioned being used more generally than the second. 

 Other arsenicals that may be substituted for the arsenate of lead are 

 arsenite of zinc and Paris green. The arsenite of zinc is a good poison, 

 but has not given general satisfaction because of its liability to burn 

 fruit and foliage. It is. however, used considerably for the first or calyx 

 sprayinir. as little damage seems to result from its application at this 

 time. Later applications are dangerous. Paris green, when substituted 

 for these others, should be applied with milk of lime in small quantities, 

 to prevent burning. 



Strength of Spray. 



A is. nate of lead in the paste form should contain from 12 to 17 per 

 cent arsenic oxide. Three or four pounds of this paste to 100 gallons of 

 \\atcr is of sufficient strength to kill the larvae. It is probably a good 

 plan to increase the strength somewhat for the later sprajdngs, applied 

 for the purpose of coating the fruit. The powdered form of lead 

 arsenate contains about double the amount of arsenic oxide per pound, 

 hence only one half as much is necessary for a given amount of water. 

 The same is true of zinc arsenite. Paris green should be used at the 

 strength of one and one half pounds to 200 gallons of water, with the 

 addition of about ten pounds of strained milk of lime. 



