io6 FRUIT TREES AND THEIR ENEMIES 



and as regards the substances recommended for its 

 destruction. 



Details as to the meaning of '' caustic emulsions " 

 and "weak emulsions " will be found on p. 6i. 



January to March. — Spray trees with a caustic 

 paraffin emulsion for cleansing them of dead bark, 

 and destroying moss, lichen, mussel scale, small apple 

 ermine moth, gooseberry and currant scale, gooseberry 

 spider, currant shoot and fruit moth, pear leaf-blister 

 mite, plum leaf-curling aphis (if the application is in 

 March), and, possibly, other insects. If the caustic 

 emulsion made with copper sulphate is used, fungus 

 spores will also be destroyed. An application once 

 every second or third year is generally sufficient, and 

 February or March is the best time to make it. 



If various lime washes are being used for special 

 purposes, these will serve as fairly good substitutes 

 for the above caustic wash. The lime-salt wash (12), 

 or the lime-sulphur-salt washes (22 and 23), may be 

 applied early in January to protect buds from birds ; 

 or the lime-salt wash (12) may be applied towards the 

 end of February to prevent hatching of plum aphis 

 eggs, or from the end of February to the middle of 

 April to prevent apple psylla from hatching. 



In late winter the ground may be dressed with 

 gas lime to destroy various pests hibernating in it. 



March or April. — Spray gooseberries with w^eak 

 emulsion for gooseberry red spider and for scale ; also 

 currants for scale, and (perhaps) raspberries for the 

 stem-bud caterpillar. Spray peaches for leaf-curl 

 with Bordeaux mixture {ga or 9^:) or Bordeaux emul- 



