156 EXPERIMENT STATION RECORD. [Vol.38 



Combination Sprays in 1916, by W. H. Brittain (pp. 9-12) ; How to Collect and 

 Preserve Insects, by L. A. DeWolfe (pp. 12-15) ; The Nova Scotia Division of 

 Entomology, by W. H. Brittain (pp. 15-17) ; The Effect of Certain Combina- 

 tions of Spraying Materials on the Set of Apples, by G. E. Sanders (pp. 17-21) ; 

 Tlie Acrididje of Nova Scotia, by C. B. Gooderham (pp. 21-30) ; Notes on the 

 Apple Seed Chalcis (Syntomaspis druparum), by W. H. Brittain (pp. 30, 31) ; 

 Biting Insects Injuring the Fruit of the Apple in Nova Scotia, by G. E. Sanders 

 (pp. 31-33) ; Notes on Two Species of Tree Hoppers (Membracidje) Ovipositing 

 in the Apple, namely, Ceresa taurina and C. bubalus, by W. H. Brittain (pp. 

 34-39) ; Arsenate of Lead Versus Arsenate of Lime, by G. E. Sanders (pp. 

 40-45); The Dock Sawfly (Ametastegia glabrata [Taxonus nigrisoma]), by 

 A. G. Dustan and F. C. Gilliatt (pp. 45-48) ; Notes on the Rose Leaf hopper 

 (Empoa rosw) in Nova Scotia, W. H. Brittain and L. G. Saunders (pp. 48-51) ; 

 Notes on the Rosy Aphis {Aphis malifolia;) in Nova Scotia, by W. H. Brittain 

 (pp. 51-55) ; and The Toxic Value of Some Common Poisons Alone and in 

 Combination with Fungicides, on a Few Species of Biting Insects, by G. E. 

 Sanders and W. H. Brittain (pp. 55-64). 



Experiments by Sanders on a small scale indicate what other field observa- 

 tions, show, namely, that with excessively dilute fungicide solutions or alone 

 arsenate of lime is highly dangerous to foliage, but in some manner normal solu- 

 tions of lime-sulphur, barium tetrasulphid, Bordeaux, and to a great extent 

 solutions of sodium sulphid (soluble sulphur) protect arsenate of lime from 

 the carbon dioxid of the air and so reduce or prevent injury fi-om it. His con- 

 clusions are substantially as follows : 



Arsenic in arsenate of lime is much cheaper than in arsenate of lead, in Nova 

 Scotia being less than 55 per cent of the cost in arsenate of lead. Per content 

 of arsenic there is slight difference in killing power in favor of arsenate of lead. 

 Arsenate of lime is more desirable from every standpoint to use with sulphid 

 sprays, but should never be used alone on foliage. Lead arsenate is the best 

 poison to use alone. Lead arsenate seems to work slightly better with Bor- 

 deaux mixture, but arsenate of lime is cheaper, so that the question of which 

 to choose for use with Bordeaux mixture is a matter of convenience. 



The studies by Brittain on the rosy aphis in Nova Scotia are in continuation 

 of those reported in a paper previously noted (E. S. R., 35, p. 853). Data re- 

 lating to the generations of the rosy aphis in 1916 are presented in tabular form 

 jiud a chart is given showing the occurrence of ten generations during the year. 



In reporting tests of the toxic value of some common poisons, both alone and 

 in combination with fungicides, Sanders and Brittain present data, largely in 

 tabular form, relating to their effect upon the brown-tail moth, tent caterpillar, 

 fall cankerworni, white-marked tussock moth, and fall webworm. " From a 

 study of these tables we find that the carrier of the poison, i. e., the fungicide 

 to which it is added, has a very marked effect on its efficiency. The effect of 

 each, calculated from the average total, may be summarized as follows : 



" The four poisons used in this experiment [arsenate of lime, barium arsenate, 

 triplumbic lead arsenate, and acid lead arsenate], when employed in combina- 

 tion with sodium sulphid (soluble sulphur) were 13.1 per cent more efficient 

 than when used alone. When the poisons were added to a mixture of barium 

 tetrasulphid and sodium sulphid their efficiency was reduced by 6.4 per cent, 

 while, added to lime-sulphur the reduction in efficiency amounted to 19.2 per cent. 

 Barium tetrasulphid reduced their toxic value 16 per cent and Bordeaux mix- 

 ture 43.5 per cent. 



" It would thus appear that with one exception, fungicides inhibit the action 

 of arsenical poisons used in combination with them, the exception being sodium 

 sulphid, whicli noticeably increases their killing power. This very marked effect 



