2<)2 REPORT OP OFFICE OF EXPKIUMENT STATIONS. 



In proparinp: this niixturo 1 poniul of Paris pjreon was stirred in 1 

 pint of crndo oil, after which llic mixture was added to 4 or 5 

 j)ounds of lime freshly slaked. The whole should then Ix^ stirred so 

 :is to cause the oil and lime to unite, and should he diluted so as to 

 make 150 <<:allons. The California Station reconnnends that the first 

 cam|)ai<2:n a<2fainst the codlin"; moth be undertaken upon the trees in 

 hloom immediately after the ])etals fall. The spi"ay at this time 

 should he directed against the ends of the blossoms from above. The 

 second cami)ai<;n should be be<i:un about the time when the first e^fi^s 

 are dej)osited npon the trees. Tn some localities this period occurs 

 much later than in others. The object of the second application is to 

 cover iniiforndy all ])arts of the tree, and a nozzle should be used 

 which will <jive a fine s})ray. In California it is believed that the 

 third campaii»;n is the most important one, and the aim of this opera- 

 tion is to poison the surface of the fruit so as to prevent the worms 

 from entering the side. According to the experiments carried out 

 in California, there is a greater danger of injuring the foliage at 

 the third application than at previous sprayings. 



During insecticide work in Delaware" for the control of the cod- 

 ling moth it is found that arsenate of lead used at the rate of 1 pound 

 to 50 gallons of water gives from one-third to one-half more benefit 

 in sound fruit than Paris green, green arsenoid, or arsenites of lime. 

 The last three arsenicals proved to be about of equal value. More 

 than 1 pound of arsenate of lead to 50 gallons of Avater or 1 jjound 

 of Paris green to IGO gallons is apparently unwarranted. It is 

 believed, as a result of the experiments in Delaware, that three appli- 

 cations are not necessary if the first two are thoroughly made. The 

 addition of adhesives to arsenical sprays was not found to be 

 profitable. 



In Idaho'' one application of Paris green before the calyx had 

 closed was found to destroy about 41 per cent of the larva» of the 

 first brood. This application seemed to be about six times as effective 

 on larvae which attempted to enter the calyx as on those which 

 entered the side of the apple. From the use of bands an average of 

 215 larva? per tree were collected. In Idaho it is recommended that 

 in all cases the first application be made just after the petals fall 

 and before the calyx closes. It was found impossible to control the 

 codling moth with one or two applications, and three or four spray- 

 ings are recommended for most localities. 



In Michigan '" spraying for the codling moth has long been prac- 

 ticed and has been found effective. Paris green applied just after 

 the petals fall and inside the calyx dries and remains for an indefi- 

 nite period. The larva; which attempt to enter through the calyx 



a Delaware Sta. P.ul. 50. 6 Idaho Sta. Buls. 21, 3G. 



c Michigan Sta. Bui. 222, 



