THE APPLE-BARK SCALE. 79 



trees a thorough scrubbing with a hard brush, using hot 

 kerosene emulsion for the purpose, is the best plan which 

 I know of to check Scale of any kind upon the stems 

 of trees. 



When the insects have securely fastened themselves to 

 the branches, the task of destroying them becomes more 

 difficult, and only by spraying the trees thoroughly with 

 either the strongest washes, or with the excellent resin 

 compound, as recommended by Mr. Koebele, the well 

 known American entomologist, and others. All prun- 

 ings of the trees should be gathered up and burned, and 

 no rubbish of any kind should be permitted to remain in 

 any well-kept orchard. During the winter is the best 

 time to tackle these little pests, because the trees being 

 then without leaves the spraying can be done in a more 

 thorough manner, which when the trees are in leaf is next 

 to an impossibility ; still, even at this time the Scale will 

 require at least close attention. 



Painting the tree with a weak solution of corrosive 

 sublimate should be tried first on a small scale.* I have 

 great hopes of this as a preventative against Scale, &c. 

 The use of common starch for destroying Scale insects is, 

 by some, thought to be an excellent remedy, but the starch 

 would, I think, be of more use in treating for the Red 

 Scale of the orange and lemon, as the soot fungus ( Capno- 

 dium citri) is generally found where the Orange Scale is 

 bad, this singular fungus being parasitic on the sugary 

 secretion of the scale insects, as also on similar secretions 

 of the Aphidce, &c. ; and, as Mr. Maskell has with truth 

 said, "the first effort of the gardener, on the appear- 

 ance of the sooty blight on his plants, should be to discover 

 the insects on its leaves or bark, and deal directly with 

 them. Once they are destroyed, the fungus growth will 

 in a short time disappear;" and as the females of the 

 Coccidce are enabled to bring forth young without the 

 assistance of the male, it is (as Mr. Maskell remarks) one 

 of the most mysterious things in nature. 



* The solution should be a very weak one, and should be used with great caution 

 and only as an experiment. 



