53 



Weiss (H. B.). Popular and Practical Entomology. Graphic Presenta- 

 tions of Entomological Facts. — Canadian Entomologist, London, 

 Ont., xlix, no. 11, November 1917, pp. 365-371. 



The author points out the desirabihty of presenting entomological 

 facts in a graphic and easily assimilated manner ; in particular he 

 advocates the use of graphs to replace tables of figures, or to illustrate 

 the text. Several examples of suitable charts, graphs and maps are 

 given. 



Ferris (G. F.). A New Genus and Species of Coccidae. (Hemip.; 

 Homop.) — Canadian Entomologist, London, Ont., xlix, no. 11, 

 November 1917, pp. 375-378, 4 figs. 



The new genus, Stomacocciis, is erected in this paper, the type, 

 S. platam, sp. n., having been taken on the leaves, branches and trunk 

 of Platanus racemosa (sycamore) in California. The insect apparently 

 hibernates on the bark and then crawls to the leaves. The life-cycle 

 is probably quite short, all stages having been found on leaves scarcely 

 a month old. 



Whetzel (H. H.). Dusting as a Substitute for Spraying : History and 

 Progress. — 48th Ann. Rept. Fruit Growers'' Assoc. Ontario, 1916 ; 

 Toronto, 1917, pp. 37-47. [Received 3rd December 1917.] 



There have been two periods in the history of dusting as a substitute 

 for sprapng for the control of apple disease in North America. The 

 first extended from about 1900 to 1908 at a time when Bordeaux and 

 Paris green were the standard fungicide and insecticide respectively, 

 the dust mixtures tested being of the same nature. The most 

 extensive tests were made in Ilhnois, with such decisively unsatis- 

 factory results that dusting was entirely abandoned by experiment 

 stations. It should be noted that this failure was due to the use of a 

 fungicide and insecticide unsuitable for application in a dry form, 

 and that the machinery used was primitive and not well adapted for 

 orchard work. Since 1909, lime-sulphur and arsenate of lead have 

 largely replaced Bordeaux and Paris green for the spraying of apples, 

 the change being marked by a distinct advance in disease and insect- 

 pest control. In 1911 another step in the progress of disease control 

 was made by the substitution of dusting for spraying ; the advantages 

 are greater rapidity in making applications, there being seldom more 

 than 1-4 days in which a given application may profitably be made, 

 and the use of an outfit that ehminates heavy machinery and tons of 

 water, at a time when the ground in orchards is soft and heavy. 

 Experiments made in 1916 to test the relative values of spraying and 

 dusting, resulted in favour of the former, owing to inexperience and the 

 use of coarse sulphur and imperfect machinery in a season exceptionally 

 favourable to scab. It is expected that with increasing experience, 

 improved dusters and finer sulphur, better results will be secured with 

 dusting than with spraying. 



As regards the relative cost of the two methods, hitherto that of 

 dusting has been rather higher, owing to the coarseness of the sulphur 

 used, which has made it difficult to cover the trees thoroughly, but 

 with finely ground sulphur and improved dusting machinery, there 

 should be little, if any, difference in cost. 



