PESTS 65 



the young shoots to become distorted. The leaves 

 also become discoloured, and the openings in them 

 become blocked by the droppings and sticky "honey- 

 dew " excreted by the insects. The aphides are always 

 green in colour, and, in certain stages, have darker 

 markings on the body. They are often covered with 

 a grey meal. Winged forms occur in July and August, 

 and fly from tree to tree. The egg-laying generation 

 occurs in late autumn in the form of small yellowish 

 lice on the under surface of the leaves, which crawl 

 on to the shoots subsequently, and there lay their 

 eggs. 



Remedies. — Spraying, to be effectual, must be done 

 before the leaves curl, preferably about the end of 

 April : weak paraffin emulsion (i6<5, by preference), or 

 nicotine (26), should be used. Much benefit results 

 from spraying in autumn with a stronger paraffin 

 emulsion, containing about 6 per cent, of paraffin, or 

 with a lime-sulphur-salt wash (22 or 23). 



The Rosy Leaf Aphis {Aphis sorbi). — This aphis 

 works very like the preceding one, but the leaves 

 attacked by it are more tightly curled, and become 

 pale yellow or rosy red. The aphis is at first 

 green or yellowish, but becomes dull blue, slaty or 

 purple, and is covered with meal ; in other stages it is 

 rusty red to pink : the egg-laying female is lemon- 

 yellow. The eggs hatch out in April, and the aphides 

 disappear from the apples at the end of June and 

 early in July, but come back again in September 

 and October. They lay black ova on the spurs, 

 axils of buds, shoots, and trunks of the trees, but 

 5 



