303 



course of these observations, it is hoped to secure some parasites 

 from material now in hand. A bug, Podisus spinosus, DalL, has been 

 recorded as vigorously attacking the larvae of E. acraea, and Apanteles 

 rileyanus, Ashm., is parasitic on them. Collections of the caterpillars 

 in the field showed that large numbers are killed by fungous and 

 bacterial diseases. 



Sandees (G. E.) & Kelsall (A.). A Copper Dust. — Proc. Entom. Soc. 

 Nova Scotia for 1918, Truro, February 19 19 , pp. 32-37. [Received 

 21st May 1919.J 



During the summer of 1918, extensive tests were made with a 

 dust mixture of 5 per cent, metallic copper and 2 per cent, metallic 

 arsenic as a substitute for liquid Bordeaux spray. For these experi- 

 ments, 20 lb. of crystal copper sulphate were roasted until dry and 

 white and then ground finely enough to pass a screen of 100 meshes 

 to the inch. This gave 12^ lb. of white powdered de-hydrated copper 

 sulphate, to which were added 7^ lb. dry calcium arsenate (40 per cent. 

 AS^Oj,) and 80 lb. hydrated lime. This mixture was thoroughly stirred 

 and apphed with a dust blower. For apples the formula was halved, 

 making 2| per cent, metallic copper to 1 per cent metalhc arsenic. 

 It is hoped that this mixture may be further improved by grinding 

 the copper more finely and by the use of a better dusting arsenate, 

 such as is being developed for use on cotton. The results of the use 

 of the dust on potato and apple are given and are considered to show 

 a decided advantage over Bordeaux mixture. The dust adheres well 

 to the foliage even when dry, and as soon as dew has fallen or if the 

 leaves were damp at the time of application, the foKage at once has 

 the appearance of having been drenched with Bordeaux mixture. 

 The dust can be stored for some months without deterioration. The 

 question of the cost of the two methods is discussed, and it is pointed 

 out that while the completed dust mixture would probably cost 

 about 60 per cent, more than liquid material necessary to spray the 

 same area, the cost of application is so much less that the dust method 

 should prove on the whole considerably less expensive. 



It is not considered that this dust has yet reached the standard to 

 be recommended to the practical grower. The formulae have yet 

 to be worked out for use on various plants. It is unhkely that the 

 dust can be used for the first application after blossoming on the 

 apple because of the danger of russeting the fruit. It will probably 

 be several years before the various formulae have been satisfactorily 

 worked out, and their relative efiiciency as compared with liquid 

 Bordeaux mixture thoroughly tested. 



Whitehead (W. E.). Notes on the Life History and Immature Stages 

 of Three Common Chrysomelids.— Proc. Entom. Soc. Nova Scotia 

 for 1918, Truro, February 1919, pp. 38-50, 2 plates. [Received 

 21st May 1919.] 



Larvae of DisonycJia qiiinquevittata, Say, were reared from golden 

 rod {Solidago squarrosa), which is apparently their exclusive food. 



