REPORT OF THE SOCIETY 21 



Canada" by Mr. A. Gibson; "Camp Hygiene" by Capt. G. J. Spencer, 

 dealing mostly with *camp hygiene as conditions were dealt with in Camp 

 Borden; "Experiments in the Control of the Apple Maggot" by Prof. 

 W. H. Brittain; "Summary of experiments on the control of Locusts 

 with Coccohacilliis acridioriim' by Mr. E. M. Du Porte and J. Vander- 

 leck; "Three Shade Tree Insects," by J. M. Swaine; "Notes on some 

 Insects of the Season" by Mr. L. Caesar; and "Parasites of the Larch 

 Sawfly" by Dr. C. Gordon Hewitt. 



One of the most important and interesting matters brought up at the 

 meeting, was the subject of dusting, introduced by Prof. L. Caesar, who gave 

 us an intersting and instructive paper on his experiments in the use of dust 

 instead of liquid sprays during the season of 1916. Although one season's 

 results are not considered absolutely conclusive, the results were very favor- 

 able as far as the work of the Provincial Entomologist was concerned. His 

 report is here summarised : 



A careful and somewhat extensive test was made on apples, plums, 

 cherries and grapes of the pew method of treating diseases and insects by 

 dusting them with a mixture composed of 85% very finely ground sulphur 

 and 15% arsenate of lead powder. Wherever, as in the case of grapes, an 

 insecticide was not required the arsenate of lead was omitted. The dusting 

 was made by means of a blower driven by a 23^ h.p. gasoline engine. The 

 results on a block of ninety- two very large and neglected apple trees were, at 

 the time of picking, an average of 97% of fruit free from scab and a little over 

 90% free from Codling Moth. On a liquid sprayed plot in the same orchard 

 where lime-sulphur and arsenate of lead paste were used, the result was an 

 average of 99%of the fruit free from scab, and about the same percentage free 

 from Codling Moth as with the dust spray. Untreated orchards of the same 

 varieties of fruit in the Niagara district where the experiments took place 

 had an average of 40 to 50% only free from scab and 30 to 60% free from 

 Codling Moth. 



There is no doubt that wet weather washes off the dust spray much 

 more quickly than the liquid, and under the circumstances Mr. Caesar 

 thinks it better not to advise dusting yet, until more experiments have been 

 made under all sorts of conditions, and his stand is certainly a wise one. 



