I20 Bulletin 142. 



that eggs have been seen on apples on the tree until the fruit has 

 reached nearly the size shown at a and b in figure 131, or until it is 

 from one-half to three fourths of an inch in diameter. 



We have gone into some detail to bring out the above facts, not 

 only because they correct some old stereotyped notions, but because 

 they have a very important bearing on the question as to when it is 

 necessary to apply the spray to reach the worms most successfully. 

 As will be brought out more fully, with illustrations, in our discus- 

 sion of the time to spray, it is necessary for fruit growers to watch 

 the blossoming of their trees and especially the development of the 

 young fruit, for therein lies an easy and sure method of determining 

 just when the spray can be applied to do the most good. 



Habits of the Moth. 



It has long been known that the adult insect was nocturnal in its 

 habits, usually remaining hidden during the day. The fact that the 

 moth closely mimics the bark in its coloring, and its habits of moving 

 about only at night, account for the fact that but few fruit-growers 

 have ever seen it. Koebeie gives the following account of their habits 

 in California: " On a hot and sunny day, while walking through an old 

 apple orchard at 10 A. m., moths started up either from the trunk or 

 lower leaves of nearly every tree and settled down again, generally 

 higher up and on the upper sides of the leaves exposed to the sun. 

 From May 25 until the end of June there could be seen at dusk from 

 25 to 50 on each tree. The place is situated on the east side of the hills. 

 About half an hour after the sun disappeared behind the mountains, 

 and while it was yet visible for nearly that length of time on the 

 opposite hill, the moths began to appear, flying with quick movements 

 around the trees, chiefly near the tops, and settling down again upon 

 the leaves or fruit from time to time. This was kept up until towards 

 dark when they became less numerous. During this time both sexes 

 may be readily collected with a long butterfly- net. I have taken 

 many near the ground on the lower leaves and often distant from fruit 

 trees. By their peculiar flight they are easily distinguished from any 

 other species of moth." Ooethe found in his experiments in Germany 

 that the moths were the most active about 9 p. m. Most of the eggs 

 are thus doubtless laid in the evening. 



