54 Second Report on Economic Zoology. 



Fumigation with Hydrocyanic Acid Gas. 



Mr. J. A. Eichniouds, of Woodlands, Lustleigh, South Devon, 

 wrote asking for information re fumigation for Mealy Bug. The 

 following reply was sent :- - 



" With regard to fumigation with hydrocyanic acid gas, I can 

 confidently say that the eggs of Mealy Bug are not all killed. In 

 my opinion, two fumigations are necessary at ten days' interval. 



" The quantities to use are : 5 ozs. sulphuric acid, 3 ozs. cyanide 

 of potassium, 8 ozs. water, to every 1000 cubic feet. 



" If the house is more than 10,000 cubic feet another jar will be 

 required, and for every additional 10,000 cubic feet. 



" The water should be put in a jar and then the acid added to it, 

 the cvanide in small lumps wrapped in blotting-paper ; the cyanide 

 is then dropped into the jar with the acid and water and allowed to 

 stand for one hour. 



" This must be done quickly, as the fumes are poisonous to man, 

 and all, or nearly all, animal life. 



"The cyanide should be dropped into the acid and water from 

 outside the house. 



" Temperature of house never more than 60° Fahr. 



" Do not fumigate in strong light. 



" Do not fumigate vines in bloom. 



" Fumigate (i) before the vines bloom ; and (ii) after the crop has 

 been gathered. 



■' The house must be well ventilated for at least one hour after 

 fumisation before anvone is allowed to enter." 



Field Mice damaging Apple Trees. 



Quite a new attack upon fruit trees has been recorded by Mr. 

 Hammond, of Canterbury. On the 2nd of April Mr. Hammond 

 wrote that " a few days ago I was looking over some apple trees in my 

 garden, when I came upon one with the spurs right up to the very 

 top of the tree gnawed all around by some animal. I have never seen 

 anything Like it before, but I think it must have been done either by 

 a squirrel or field mice. The material was examined, and the 

 following reply sent : — 



" I think the damaged twigs of apple you send have been eaten 

 by field mice, not by squirrels ; the marks of the teeth do not seem 

 large enough for the latter. I have never seen any such damage i-n 



