124 PROTECTION OF WOODS 



fungus finding a ready inlet through the wounds caused by 

 the aphis. At first the insects are wingless, but they acquire 

 wings in late summer, and then spread to other larch and to 

 the spruce. 



Nothing can be done on a large scale against this insect, 

 and one must trust to keeping larch healthy by growing it 

 only in favourable places. Nursery plants, if attacked, may 

 be sprayed with paraffin emulsion. 



Beech woolly aphis (Coccus fagi). 



This scale insect attacks beech, and is becoming a serious 

 pest, often killing fine old trees. It is covered with a white 

 felt, which is very conspicuous on the bark where the insect 

 sits and sucks the sap. Valuable trees in parks may be saved 

 by scrubbing them from top to bottom, wherever the insect 

 is seen, with the paraffin emulsion. Further details regarding 

 this pest may be found in the Board of Agriculture leaflet 

 No. 140. It is apparently amenable to some 'influence, possibly 

 the weather, as there has lately been observed a considerable 

 diminution of the pest in some of the beech woods in 

 Buckinghamshire. 



