22 



WHEN TO SPRAY FOB, THE CODLING MOTH AND THE SCAB. 



It is practicable to combine most of the sprayings for the codling 

 moth and apple scab and thus lessen b}^ one-half the cost in time 

 and labor. The arsenical ma}' be added to the diluted Bordeaux mix- 

 ture at the same rate as to pure water, and the lime in the Bordeaux 

 mixture will act as an additional preventive of scalding from the 

 arsenical and obviates the necessity of adding lime to take up free 

 arsenic. The dates of spra3dng for the first brood of the codling 

 moth and for the apple scab are the same except for the first treatment 

 for the scab, which should be made after the leaf buds unfold but 

 before the flower buds open, and is the most important application for 

 this disease. The arsenical in this first application has no relation to , 

 the codling moth, which has not yet appeared, and it is sometimes 

 omitted; but its addition costs very little, and it will reach the canker- 

 worm, bud moth, and curculio. The subsequent sprayings appl}^ to 

 both the codling moth and the apple scab, and the arsenical should 

 alwa3^s be added to the Bordeaux mixture. The second sprajdng 

 should be made just after the blossoms fall and before the calyx closes, 

 and is the most important of the sprayings for the codling moth, 

 getting the poison into the open calyx, where it will subsequently 

 destroy the larvse before the latter can penetrate into the apple. The 

 third spraying should follow in seven or eight da^^s, and the fourth 

 three weeks later. In the case of the codling moth these destroy the 

 young caterpillars on the leaves before they reach the fruit and in 

 their feeding about the calyx, and assist in the control of apple scab. 

 A fifth combined spraying may be given thirty days subsequent to 

 the fourth, but this is optional in the case of both pests and will 

 depend on the amount of probable infestation of either codling moth 

 or apple scab. 



Later spra3dngs against the codling moth are directed against the 

 larvae of the second generation when the}' are entering the fruit, and 

 need not be combined with the Bordeaux treatment for the scab. The 

 time for this spraying for the codling moth will vary with locality and 

 seasons. The larvae of this second generation enter the fruit begin- 

 ning with the last of July and extending through August and Septem- 

 ber. The number of spraj'ings to be made against this second 

 generation depends upon the efficiency of the preventive measures 

 and of the early sprayings. Two of these later sprayings are usually 

 sufiicient, and may be made, respectiveh', during the last week in July 

 and about the middle of August. The quantit}^ of lime used in the 

 last spraying should be reduced to not more than 1 pound to the pound 

 of arsenical to avoid a limy coating on the ripe fruit. 



Light showers have but little effect in washing away the spi'a}^ but 

 a continued rain or heav}' shower may make it necessary to repeat the 

 application. 



