EXPERIMENT STATION BULLETINS. 191 



A comparison between these figures shows that in an equal number of fruits 

 and leaves, viz., 1,150 each, nearly 19% of the eggs were laid on the leaves. 



In order to get an idea of the proportion of eggs that were laid on the foliage 

 as a whole as compared with the number laid on the fruit, a count was made 

 of the leaves and fruits on a part of a good bearing tree in the College orchard. 

 On September 15, 1904, a limb 3i/>? inches in diameter, which had been split from 

 the tree by the wind, was removed from the tree and each leaf and apple picked 

 off and counted at the time. The result was as follows, — 986 apples and 26,395 

 leaves, or 26 8 times as many leaves as apples. A count of 1,150 leaves and 1,150 

 apples, gave us 69 eggs laid on the leaves and 295 eggs laid on apples. This gives 

 us 13.767o of the eggs laid on the fruit as against 86.24% on the foliage. Further- 

 more, the young larvae were found to feed on the underside of the leaves, re- 

 moving small patches of the soft tissue. This helps to explain why the August 

 spray is so efficient, for it is much easier to make the spray cover and stick to a 

 leaf, than to an apple. 



EXPERIMENT IN SPKATING FOE THE CODLING-MOTH. 



In order to put to a practical test, the effect of two sprays, applied as indicated 

 by the calendar, permission was obtained to spray an orchard of about forty trees. 

 In the vicinity of the College. Accordingly a spray of paris-green and bordeaux 

 was applied, using four pounds of copper sulphate, six pounds of lime and 40 

 gallons of water, to which was added four ounces of paris-green. This was care- 

 fully put on on June 3, 1904. A second spray was applied on August 9, using four 

 ounces of paris-green and eight ounces of lime to 40 gallons of water. Examina- 

 tions of 60 apples made on July 13 showed three larvae or 5%; there were evi- 

 dence of more which had* entered into the calyx, but had died there. Another 

 examination on August 31 showed three live larvae with three more that had 

 died in trying to gain entrance. 



On October 15, 1904, three trees were picked and the fruit sorted as carefully 

 as possible without cutting open each apple. One tree (No. Ill) was unsprayed 

 because of its location, being difficult to get at. This tree was the best one of a 

 group of four unsprayed trees standing near together. It had borne well and 

 would have produced a fine lot of fruit had it received the same treatment as 

 the others. The fruit was, however, scabby, and a large number of wormy apples 

 had fallen. The variety of trees I to V was Northern Spy. A count from this 

 tree gave the following result: 



TREE III. UNSPRAYED, IN SPRAYED ORCnAED. •^ 



Yield -. 12 bu. 



No. of apples 1,560 



Not wormy 897 



Wormy 663 



Per cent wormy 42.5 



The reason for the vastly superior yield of this tree over that of trees IV and 

 V, in the unsprayed orchard is easy to see. The sprayed orchard was better 

 pruned, cultivated, and fertilized, and the percentage of sound fruits was raised 

 because great numbers of the moths from this tree spread themselves over the 

 rest of the orchard, while few moths from other trees came to this one. The 

 difference in the yield was largely due to culture, but the difference in the per- 

 centage of wormy fruit was largely due to the fact that the surrounding trees 

 were well sprayed. 



Two other trees that had been sprayed twice, as previously described, were 

 examined on the same day. Tree I was considerably further away from tree 

 III than tree II. An examination of tree II gave the following results. There 

 was little scab. 



TREE II. — SPRAYED TWICE. 



Yield 13 bu. 



No. of apples 1,706 



Not wormy 1,483 



Wormy 223 



Per cent wormy 13.07 



