PROCEEDINGS, 1917. 15 



THE WORK OF THE DOMINION ENTOMOLOGICAL 

 LABORATORY IN NOVA SCOTIA. 



By G. E. Sanders, Entomological Laboratory, Annapolis Royal, N. S. 



THE WORK of the Dominion Entomological Laboratory at Annapolis Royal, 

 as arranged at the present time, consists in carrying on in conjuction with other 

 departments, a vigorous campaign for more spraying, thereby not only assist- 

 ing in the production of more and better fruit, but also assisting in the control of the 

 brown-tail moth, and preparing the country for outbreaks of even more serious insects 

 such as the gypsy moth, which is expected at any time, and in the testing of insecticides, 

 both alone and in combination with various fungicides for their effect on insects and on 

 the foliage and fruit of the plants sprayed. In addition to this work the general rou- 

 tine work of such a laboratory is carried on, insect injury identified and enquiries of 

 a general nature answered. 



For a staff, we have in addition to myself, Mr. A. G. Dustan, who attends to the 

 testing of the insecticides in the laboratory getting the effect of each poison and com- 

 bination of poison and fungicide on the insects fed; Mr. A. Kelsall, who on account of 

 his knowledge of chemistry, as well as biology, acts as adviser in our work of combin- 

 ing the various spraying materials, and who is at the present time doing most excellent 

 work on the action of spraying material on the fruit and foliage; Mr. F. C. Gilliatt, 

 who does most of our field experiments in apple spraying; and Mr. S. H. Payne, who 

 acts as photographer, alnd who has up to date done most of our experimental work on 

 potatoes. 



Having published practically all of our 1916 work and not yet completedour work 

 of 1917, it is impossible at the present time for me to give you any definite results. As 

 Prof. Brittain has asked me for a short paper only, I shall outline to you our method 

 of work up to date on apple spraying. 



Soon after starting work on apple sprays in 1915, we discovered that the then uni- 

 versally recommended lime and sulphur 1 gallon, paste lead arsenate 2 lbs., to 40 gal- 

 lons of water, was not all that it should be in giving healthy foliage and in full crops of 

 clean, good keeping fruit. We were told that Bordeaux was barred from an apple spray 

 calendar on account of it russetting the fruit and that sodium sulphides (soluble sul- 

 phur and sulfocide) were useless because they could not be combined with arsenicals. 

 Lead arsenate was regarded as a stomach poison which had great value as an adhesive 

 and so added to the fungicidal value of the lime sulphur solution, when used with it. 



Upon investigating the combination of lead arsenate 2 lbs., and lime sulphur 1 

 gallon, to 40 gallons of water, we found that when applied two weeks after the blos- 

 soms fell, it frequently caused from 10 to 80 per cent of the crop of apples to drop off 

 the trees, depending on the thoroughness of the application, that it caused a great am- 

 ount of leaf roll or curl, and gave a most inefficient leaf; that the addition of lead arsen- 

 ate to the lime and sulphur caused the loss of some 30 per cent of sulphur from solution 

 as lead sulphide, and the consequent formation of mono-, bi-, and tricalcic arsenate, five 

 per cent of which was soluble was responsible in a large measure for the burning which 

 resulted from the combination. The lead precipitate was a nuisance both in the tank 

 and pump and useless on the trees. There seemed, therefore, a great deal wrong with 

 the lime sulphur-lead arsenate combinations as recommended in 1915. 



In getting the problem of sprays solved, we began investigating the good and bad 

 points of each of the well known spraying solutions, which investigating we have not yet 

 finished. We have, however, obtained some interesting and valuable results. 



Bordeaux we have found cannot be used for spray immediately after the blossoms 

 fall, on account of russeting the fruit. It can, however, be used for the pre-blossom 

 sprays and for the sprays applied two weeks after the blossoms fall and later with only 



