59 



bands, was to save 66 per cent. I believe that what good effects are 

 derived from its use are due to the killing of the larvae with which it 

 comes in contact. 



Many of the fruit growers add an arsenite, usually paris green, to 

 the carbolic compound. The results with this mixture are varying. 



Others have used kerosene in the arsenite, thereby combining both 

 poisonous and contact insecticide. One grower used this combination, 

 and writes me that u There are no wormy apples to be seen" (in his 

 orchard), and that the apples injured by all sources amounted to only 

 about 0.05 per cent. 



One difficulty is to get these different ingredients to mix well. 

 Whale-oil soap is used in combination with other sprays, but I could 

 find no facts in regard to the results of its use. 



By far the greater number of growers use the arsenites alone. Of 

 these arsenites paris green is most used, in the proportion of 1 pound 

 to 150 gallons of water, with from 1 to 2 pounds of freshly slacked 

 lime. 



Some are using London purple, and others are using a combination 

 of London purple and Paris green. Many are using the lime arsenite 

 with excellent results. In fact, wherever any of these arsenites are 

 used intelligently good results are obtained. Some growers are preju- 

 diced against certain of these arsenites on account of past experiences. 

 In two cases I found that they had omitted the lime, and in both cases 

 the foliage was badly burned. 



My observations have led me to believe that it makes but little 

 difference as to what arsenite is used if it is well applied. 



The pumps used were of all kinds and conditions. Many were using 

 nozzles which threw a coarse spray that was valueless. The time for 

 spraying is as essential as the spraying itself, and I wish that this fact 

 could be impressed strongly upon the Idaho growers. One can readily 

 see that a spray would do but little good when the maximum of a 

 brood are going under bands, compared with a spray when the maxi- 

 mum of a brood is hatching from the egg. To secure good results, 

 there must be at least three sprayings, and in extremety bad cases it 

 is advisable to spray six times. 



If the injury for the previous season was large, I would advise two 

 sprayings while the calyx remained open — one immediately after the 

 blossoms have fallen and the other in about a week. If, however, the 

 injury of the previous season was not large, one spraying from five 

 da}^s to a week after the blossoms have fallen may answer. In all 

 cases I would advise the two sprayings, as it is well to be on the safe 

 side. 



It has become one of the best known principles of spraying that 

 these first sprayings are the most efficient, and if it were not for the 



