The Canadian Horticulturist. 



171 



opens in the course of time and allows 

 these spore sacs to escape. The spore 

 sac protects the spores during the 

 severe weather of winter ; but, during 

 the warm weather of the early spring, 

 allows them to escape, and, being very 

 light and very numerous, enough are 

 easily blown about to continue the 

 propagation of the fungus upon the 

 young growth of ohe foliage. Fig. 538. 

 The best remedy is spraying with 

 potassium sulphide. This work must 

 be done early before the mildew ap- 

 pears on the bushes, for its action is 

 rather preventive than remedial. The 



proportion of this insecticide required is one-half ounce dissolved in a gallon of 



hot water. 



Fig. 538. 



THE APPLE TREE APHIS {Aphis Mali). 



HE apple louse often appears in immense numbers on the young 

 foliage of our apple trees, checking considerably the vigor of the 

 tree. The eggs are deposited in autumn, and remain in crevices 

 M of the bark, and about the base of the buds ; and though at first 

 light yellow, soon change to black. The lice hatched from these 

 eggs are all females, wingless, and greenish-yel- 

 low in color, with black eyes and tail ; and each 

 produce living young at the rate of about two 

 a week which are also in turn equally prolific. 

 Our illustration shows the wingless female, and 

 the winged male which is not born till late in 

 the season. The small one at the right shows 

 the natural size. 



Spraying with kerosene emulsion is the most fig. 539.— The Apple Aphis. The perfect 



fly, with tne louse enlarged on the left, 

 effective remedy. and twice the natural size on the right. 



The profit to be derived from spraying orchards often exceeds $20 per acre, 

 and for vineyards is much more. The fruit crop of any StV-~ would be 

 enhanced in value by several million dollars annually if the practice were gener- 

 ally followed. 



