The Codling Moth. 265 



out in Prof. Woodworth's paper, is that there are certain sections where it 

 is not as vitally necessary as in the North. In counting many apples we found 

 that 72 per cent of the worms entered at points other than the calyx and 28 per 

 cent entered at that point, and you can see how much less necessity there is 

 of spraying at that time in this section. 



Again the question has come up here as regards the use of lime in this 

 spray. We, in California, do not, of course, regard the lime as a poison, but 

 use it as a neutralizer of the possible free arsenic in solution in the spray. We 

 find that the eggs are not placed on either the leaves or the fruit where there 

 is fuzz or any roughness. They are laid upon the smooth leaves, and if we 

 roughen up these leaves possibly the female moth may not be tempted to place 

 her eggs upon them. This may be one reason in favor of the use of lime to 

 some extent. 



Again, our experiments in California have brought out another interesting 

 fact. It has been with the California Station, and I believe with all entomol- 

 ogists, a question as to how the worms get the arsenical poison that kills. If 

 you will go to one of the sprayed orchards and take an apple from that orchard 

 and examine it carefully, if it has been sprayed with Paris green you will be 

 able to detect the particles of that material on the apple. You will find that 

 the area that is not protected by tlae poison is much larger than the area that 

 is so protected. It would seem as if the codling worm must go out of its way 

 to get the poison. We made several interesting observations along that line 

 in our work this season. We have been able to follow the worm in numerous 

 cases from the egg until it was out of sight in the fruit. We have followed 

 the hatching process completely in the laboratory, and. not alone there, but 

 many times in the orchard. I will try and detail a typical case which may 

 show why and how the worm gets the poison. When examining several sprayed 

 trees we found an apple that liad just one drop of spray material and on this 

 apple was an egg with the worm about to hatch out. It is always desirable 

 when an observer gets a condition of this kind to follow it out, so we remained 

 and watclied operations. The worm hatched out and passed up over the surface 

 of the apple as thougli going to the blossom and , in making this passage over the 

 face of the apple it found the drop of spray material, the only spot on the whole 

 apple. It stopped continuing to spin out its silk, using the lime spot as a 

 point of mooring. I went through this process for a short time and then 

 seemed to decide that this was not a satisfactory place for its purpose. The 

 worm then passed up to the blossom end of the apple and immediately went 

 through the same tactics and then again decided tliat that was not the point 

 where it wanted to make an entry. It then crowled up to the stem of the 

 apple, and from the stem back again, after having gone lialf way out, and 

 wandering about with no apparent object upon the face of the apple, it again 

 found the lime spot, and went through the same procedure of spinning out 

 silk threads. Very soon the worm began to bite into the fruit just beside the 

 spot, and was out of sight underneath the skin of the apple in just one hour 

 and thirty-five minutes after the first observation. We kept up our observation 

 of that apple and found tiie worm forty-eight liours afterwards dead at the 

 edge of tlie burrow with all indications of arsenical poisoning. Everything 

 would seem to point to the fact that it had actually hunted up the poison and 

 taken it, unconsciously, of course. Now. this helps us to understand the reason 

 for the value of spraying. We think that though we do not completely cover 

 the apple, but put those spots around freely enough, we may get the worm in 

 the end. We have i^andled from 100,000 to 200,000 trees, ranging in age from 

 five to twenty-three years, everyyhere with reduced losses from tliis insect, 

 and on 25,000 of these trees, in various parts of the valley, we have so reduced 

 the loss that we were able to send 95 per cent of the fruit free from worms 

 to the shipping house. 



Following the rational program, as outlined in Prof. Woodworth's paper, 

 we feel satisfied that another season's work will result in better control, as 

 greater areas of orchard will be properly sprayed. 



