254 The Spraying of Plants. 



the moth is a night-flying insect, it has been repeatedly tried 

 to attract it by means of lights. Rarely is one caught, and it 

 is useless to attempt to trap the moth in this manner. 



Spraying with arsenites is rapidly taking the place of the 

 many methods which were formerly employed to destroy this 

 pest. The applications are safe, easily made, and are almost 

 invariably followed by excellent results. The first application 

 should be made as soon as the blossoms fall from the trees, earlier 

 ones being unnecessary. But as soon as the blossoms have 

 fallen, spray thoroughly, using either Paris green or London 

 purple. The operation must not be delayed until the apples 

 are as large as cherries, but should be immediately performed. 

 It is well to spray a second time about ten days later, but if the 

 weather is rainy, applications are advisable after heavy showers, 

 since the poison is more or less washed away by a beating rain. 

 Poison must be at the blossom end of the apple when the larva 

 appears, for when the worm is once inside the fruit it can no 

 longer be reached ; the first thing that it eats should be poison. 



Since the second brood comes from the first, if the first is 

 killed there can be no second, therefore the necessity of doing 

 the work well from the beginning. The appearance of the later 

 broods is probably too irregular to allow of successful treatment, 

 and it is not always advisable to make special applications for 

 their destruction. 



By applying a combination of an insecticide and a fungicide, 

 we can treat both the codlin-moth and the apple scab, thus 

 saving the labor of one treatment. The most reliable combi- 

 nation thus far made is that of the Bordeaux mixture and 

 Paris green or London purple. This combination is as effective 

 as when separate treatments are made l against the fungus and 

 the insect. The use of the ammoniacal carbonate of copper 

 applied in connection with the arsenites has also given good 

 results, and as the mixture is more easily applied than Bor- 

 deaux, it may in some rare cases be given the preference 

 (see page 140). 



In Paris green we have a combined insecticide and fungicide, 

 already prepared, but the fungicidal value is not so strong as 

 might be wished. Its use during the past two years has, 

 however, shown that it affords apples considerable protection 



i Cornell Agric. Exp. Sta. Bull. 48, 274 ; 60, 274. 



