198 THE CANADIAN ENTOMOLOGIST. 



twenty days before it emerges to spin its cocoon under some rude pro- 

 tective covering, such as rough bark, cracks, bands, etc. Six days later 

 the larva within the cocoon transforms to a pupa, and two weeks after it 

 has entered the pupal state the moth appears. The average duration of 

 the first generation is about fifty days. In districts where there is but one 

 generation in a year, the larval stage is lengthened to nearly ten months, 

 for the winter is passed as a larva within a cocoon. Where there are two 

 generations the moths emerge in August to deposit eggs on the apple for 

 the second brood of larvte, which work throughout August and September 

 in the developed fruit. This second brood of "\vorms" is more destructive 

 than the first, as their ravages are committed on the later and more valu- 

 able fruit, often after it has been picked and stored. 



From the standpoint of the control of the Codling Moth it is important 

 to know definitely when the moths deposit their eggs, and when these eggs 

 hatch. The observations of many competent entomologists indicate that 

 the egg-laying period may extend over several weeks with both generations 

 of moths. 



When we consider the problem of the control of the Codling Moth 

 we must emphasize the importance of these lengthened egg-laying periods, 

 more especially when we bear in mind the habits of the larvpe. It is clear 

 from what has been stated, that the early larvaj may be killed by poisoning 

 the leaves, and by placing poison in the calyx end of the apple; and the 

 second brood may be killed by the spraying of the fruit, for the eggs of 

 this brood are, as a rule, deposited on the fruit. 



Experiments carried out both in the East and the West show that 

 a very large percentage of worm-free apples is obtained when two 

 sprayings are made for the first brood of larvse^ and one for the 

 second brood when it is present: the first spraying a few days after 

 the petals fall; the second two or three weeks later; and the third about 

 the middle of August in ordinary seasons. Slingerland lays great emphasis 

 on the first spraying for Eastern conditions, while Simpson is of the 

 opinion that the second spraying is most effective for Western conditions. 



A very important factor in successful spraying is the arsenical mixture 

 used. Paris Green has for many years been used successfully by careful 

 sprayers, but with very indifferent results by careless sprayers. If not 

 carefully mixed and agitated Paris Green settles rapidly to the bottom, and 

 much of it will remain at the bottom of the spray barrel when the solution 

 is all sprayed out. 



