90 THE EEPOET OF THE Xo. 36 



to nine psyllas per tree. At the end of August, the orchard was still practically 

 free of i)sylla, the foilage was abundant and healthy green in colour, whereas in 

 our check orchard the trees were heavily infested, all the foliage was spotted with 

 brown and some of it was dead. The last examination of the treated orchard 

 was made in late October and rather to our surprise, we found that the insect 

 had increased to qirite an extent and that the winter adults were fairly common. 



Conclusions: Our results this year show that although the two applications 

 will not eradicate the psylla, they will reduce it to insignificant proportions. To 

 obtain absolute control, it seems to us in the light of our present knowledge, that 

 it would be necessary to spray with nicotine extract two to three weeks after the 

 calyx application in order to destroy the nymphs derived from belated eggs. 



Peof. Pakrott: Pear Psylla is next to Blight the worst pest we have to 

 contend with in the u])keep of our pear plantings, and the experience of Mr. Eoss 

 in the control of the insect resembles a great many of our experiences. Control 

 varies with seasonal conditions, and the numbers of females that hang over to 

 take part in the spring oviposition. It takes two sprays to give good commercial 

 control. A great many experiments have been carried on both by the Station and 

 by spraying experts and some years results have been almost perfect and in other 

 years or in other experiments the results have not been so satisfactory. 



Me. Eoss : I should like to ask Prof. Parrott if he can explain why the Pear 

 Psylla never seems to be troublesome in small plantings. 



Prof. Paeeott: I cannot explain it any more than I can understand why 

 roadside trees are so free from it. I think it likes sheltered, and undisturbed 

 areas in an orchard. As to what inliuences it I do not know. 



CONTEOL OF THE APPLE MAGGOT. 

 L. Caesar and W. A. Eoss. 



A full account of all our tests of control measures against the Apple Maggot 

 would require too long an article ; hence we shall give only the outstanding points 

 of interest and value. 



In 1911 and 1912 the destruction of the fallen fruit was tested in a- small, 

 isolated, badly infested orchard, and gave fairly satisfactory results, but the labor 

 involved was so great that it was seen that not many fruit growers could or would 

 adopt the method and in many cases live stock could not be used for the purpose. 



In 1913 we tried sweetened poison sprays on individual trees or groups of 

 trees in the orchards and found that though the number of infested fruits compared 

 with those on some of the checks was lessened yet the results were not satisfactory. 



In 1914 believing that a larger continuous area should be sprayed we gave 

 two applications of arsenate of lead- and molasses to a 25 acre orchard at Mountain 

 and left a narrow strip of about 2 acres along the east side as a check. Both check 

 and sprayed portion had been badly infested the previous year and much of the 

 fruit had been left on the ground. 



Eesult: In the whole orchard, after an examination in September by both 

 writers, less than a dozen infested apples were found. This no doubt would look 

 like a case of natural control and in no way due to spraying; but such was not 

 the case, because examination of the trees soon after the first application and 

 ao-ain durin"- the second showed tliat, though the flies were not abundant yet 



