304 



Spraying for Codling Moth. 



[AUG., 



was made up as follows : — Paris green, I lb ; fresh lime, 8 lb. ; 

 treacle 2 lb., added to 160 to 180 gallons of water. The arsenic 

 solution was composed of white arsenic, I lb. ; washing soda, 

 2 lb. ; fresh lime, 24 lb. ; treacle, 6 lb. ; added to 320 gallons of 

 water. Arsenic was found to be quicker in its action on the 

 insects than Paris green, but it was not nearly so lasting, and, 

 judging by results, the Paris green proved undoubtedly as good as } 

 if not superior, to the arsenic and less dangerous to the foliage. 



The method of making the Paris green solution was as 

 follows : — The fresh lime was first slaked, and then placed in a 

 barrel and mixed with water in the proportion of 1 lb. of lime 

 to each gallon of water ; this was thoroughly stirred, the treacle 

 added, and left to stand all night. In the morning this lime 

 water was drawn off and put in the vat of the spraying machine 

 with the necessary water and the Paris green added. The Paris 

 green, however, was first thoroughly mixed with about a quart 

 of the lime water. The quantity used was about 210-220 

 gallons per acre, and the cost, including labour in Victoria, was 

 about 33s. per acre, or 46. per tree. An 80-gallon pump drawn 

 by one horse and worked by three men was used. 



All the fruit was carefully examined, and while the sprayed 

 trees showed only 6 per cent, of infected fruit when Paris green 

 was used, the unsprayed trees yielded 40 per cent, of infected fruit. 

 There is, it is stated, no danger from the use of these arsenical 

 compounds, as there is hardly a trace to be found by analysis 

 on the fruit, though there is sufficient to destroy the microscopic 

 caterpillar on its emergence from the egg. The fact that there 

 were three distinct broods of moths during the season in Victoria 

 shows the necessity for frequent spraying. In England there is 

 normally only one brood in a season, but in some cases there 

 are two. 



The value of trapping the caterpillars by bandages on the trees 

 is recognised, but it is pointed out that when a caterpillar is 

 trapped a fruit has been destroyed, whereas by spraying the 

 caterpillar is killed and the fruit saved. Sprayed apples have 

 been observed with as many as twelve attempts at entrance by 

 the caterpillars, failure resulting in each case, whereas in un- 

 sprayed fruit as many as five full-grown caterpillars have been 

 found in a single fruit. 



