INSECTS AND DISEASES, 333 



infested. Whatever tree is attacked by 

 it, will speedily exhibit symptoms of its mis- 

 chief, by the foliage turning a pale sickly 

 colour, which is caused by the insect biting 

 and extracting the juices from the leaves. 

 Pure water or soap suds, applied by means 

 of a syringe or garden engine, will destroy 

 this insect; but the latter is preferable on 

 account of the ingredients of which soap is 

 composed, (and a small portion of which ad- 

 heres to the leaves after a washing with them) 

 being a preventive for a short time, of the 

 insects which survive fixing again upon the 

 foliage thus washed. The more forcible 

 the water, &c. is applied, the better the 

 effect produced, because the force of the water 

 breaks the webs of the insect, and by it be- 

 ing thus dislodged, falls to the ground and 

 is destroyed by the wet. It must always be 

 endeavoured to apply the water to the under 

 side of the foliage, as the insect is chiefly to 

 be found there. When trees are much in- 

 fested a frequent repetition of watering is 

 necessary. 



The time for washing trees out of doors, 

 should always be done just before the sun 

 leaves them, so that the trees are kept in a 

 moist state until the following morning, which 

 will be a much longer period than if applied 



in a morning. 



When trees cultivated in a house are 

 attacked by this insect, in addition to the 



