^2 NEW YORK STATE MUSEUM 



trees receiving the special treatment have 83 per cent of the wormy 

 fruit showing the " shallow " blemish, on the check trees it was 82 per 

 cent and on trees B and F, those producing the smallest percentage 

 of wormy fruit, it was 84 per cent. These ranges are very small and 

 suggest that reduction in the infestation of the orchard is the surest 

 method of eliminating the " shallow " type of injury. On the other 

 hand, it should be stated that there was no such late oviposition as 

 had obtained in earlier years when this trouble was more evident and 

 were such conditions to prevail results might be very different. The 

 information secured amply justifies further tests along these lines. 



The time for this special treatment was fixed by examinations for 

 eggs upon both leaves and young apples, specially the latter, and an 

 attempt was made to have the spraying come just before many eggs 

 were likely to be deposited. This varies from season to season 

 and appears to be intimately connected with evening temperatures. 

 It is possible that a comparatively simple rule for establishing the 

 most effective time for this treatment can be worked out in connec- 

 tion with observations upon temperatures and oviposition now in 

 progress. 



A modification of this treatment was tried July 2d on the farm of 

 L. L. Morrell, Kinderhook. Four rows of moderate sized apple trees, 

 mostly greenings and some Baldwins, were dusted with 10 pounds 

 of arsenate of lead, 40 pounds of tobacco and 50 pounds of sulphur. 

 There was a light breeze and the dust drifted through the trees and 

 covered the foliage thoroughly though there was more on the wind- 

 ward side. No codling moth work was visible at the time and later 

 developments prevented a careful classification of the fruit. Mr 

 Morrell expressed himself as very well pleased with the treatment 

 and stated that the fruit was exceptionally free from codling moth 

 injury. 



Oviposition and Evening Temperatures 



Unquestionably there is an intimate relation between evening 

 temperatures and the deposition of eggs by the codling moth. In 

 the first place very few eggs are deposited when the early evening 

 temperatures, 8 p. m. and 9 p. m. sun time, are below 60 degrees 

 and if there is a marked rise above this following a period of rela- 

 tively cool weather, conditions are favorable for the deposition of 

 large numbers of eggs. The low evening temperatures of June and 

 early July in the vicinity of the Great Lakes appear to have a marked 

 effect upon the codling moth and in certain seasons there may be a 

 very general prevalence of the " shallow " type of injury following 

 a delayed oviposition. 



