Fungoid and Insect Pests 105 



together, being kept well stirred while the mixing 

 takes place. Besides being used for destroying the 

 the curl leaf fungus of the peach and nectarine, 

 Bordeaux Mixture is also useful for suppressing the 

 black spot of the apple and pear and the shot hole 

 of the apricot, by spraying just as the flower buds 

 are opening. 



ORANGE SCALE. 



Red Scale is a small circular insect of a reddish 

 brown colour, which increases very rapidly under 

 circumstances favouring its growth, which are moist 

 and muggy atmospheric conditions. The only effec- 

 tive way of getting rid of it is by fumigating the 

 trees with hydrocyanic acid gas, which is generated 

 by treating potassium cyanide with a diluted solu- 

 tion of sulphuric acid. Fumigation is done in the 

 night time, the gas being liberated under a tent, 

 which covers the tree. For 100 to 150 cubic feet of 

 tent space the amount of ingredients generally used 

 is 1 oz. potassium cyanide, 1 oz. sulphuric acid,, 

 and 3 ozs. of water. 



The red scale, which is the most harmful of all 

 insect pests to the orange tree, has up to the 

 present time not made its appearance among the 

 orange groves of the South Australian portion of 

 the Upper Murray Valley. 



Brown Scale. This variety of the genus of 

 Lecanium, or unarmoured scales, is fairly well 

 known to the citrus growers of the Murray Valley. 

 The full-grown insect is about one-eighth of an inch 

 long, broadly oval, convex upon the disc, surrounded 

 by a thin flat margin, and of a brownish colour. 

 The scale thrives upon the bark and leaves of the 

 branches of the tree by sucking out the sap, and is 

 generally found in the greatest numbers in situa- 

 tions not directly exposed to the sun. 



