818 JOURNAL OF THE EOYAL HORTICULTURAL SOCIETY. 



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 maximum of a brood 

 is hatching from the egg. To secure good results, there must be at least 

 three sprayings, and in extremely 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 days 

 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 number of 

 broods in Idaho these, I believe, would be sufficient. In short, the poison 

 is put in the calyx cup, the calyx closes, and when the young larva enters 

 the calyx for its first few meals it gets some of the poison. As about 

 60 per cent, enter the apple at this point, it is very plain that this is the 

 golden opportunity in this combat. Professor Aldrich finds that 41 per 

 cent, of the larvae entering the calyx end are destroyed by this spraying. 

 An insect killed at this time not only saves the apple, but reduces the 

 number of the insects of the following broods. By a single spraying and 

 by banding one prominent grower tells me that he can save 50 per cent, of 

 his apples. Many people spray only once a season, and consequently the 

 effect of it is lost later in the season. If rains wash ott" these sprays, they 

 should be repeated immediately. 



The next spraying should be done when the second brood is entering 

 the fruit. Find the maximum of the preceding brood going under the 

 bands and spray about two weeks later. It would probably be better to 

 spray a few days earlier than two weeks. A few growers watch the 

 increase of spots on the apples. The later sprayings should be determined 

 in the same way. Other sprayings can be done with profit on account of the 

 overlapping of the broods, but they should be made as near the maximum 

 of egg-hatching as possible. In fact, late in the season, when the maximum 

 is poorly defined, a spray is more or less efiective at any time. Last year 

 (1900) the dates, according to band records, for most effective spraying 

 were June 10-15, July 27, and September 5. No inflexible rule can be 

 given for these dates, as each grower has different conditions to meet, and 

 seasons vary. Each grower must determine these dates for himself. The 

 greater number of the growers simply space oft' the season and spray at 

 empirical times, without regard to the stage of the insect, and obtain, as 

 a consequence, poor results. 



It has been clearly demonstrated that these few spraying alone are 

 not always sufficient to control the insect. If the sprayings were made 

 every week, the insect could be controlled, but this is too expensive. The 

 spray is effective only for a short time, and must be supplemented by 

 something to take the insects which enter the fruit between the sprayings. 

 Banding has been found to be the most efficient in this connection. 



Many people object to the use of arsenites for later sprayings on 

 account of the liability of poisoning those who eat the fruit. I believe 



