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XIII. Note on Sir Oswald Mosley's Paper, on the Aphis 

 Lanigera. By Alexander Seton, Esq. F. H. S. $c. 



Read March 3, 1818. 



I have been in the practice, for some years, of using tar, 

 for the destruction of this insect, by putting it, with a 

 painter's brush, over the parts of the stem and branches, 

 where the animal appears. This I have found to be com- 

 pletely effectual, and it operates, no doubt, in the same 

 manner as the oil, by excluding the air, and involving the 

 insects in a mass, from which they cannot extricate them- 

 selves. It may be a proper subject of experiment to 

 ascertain, which of the two methods answers best. I should 

 suppose, that the tar would be more lasting in its effects, 

 than the oil, and that it would more completely destroy any 

 young insects that might be produced from the latent eggs, 

 a considerable time after the application. It is to be ob- 

 served, that tar will destroy the leaves and the young shoots, 

 which are in an herbaceous state, where it touches them ; 

 but I have never found it to be injurious to the ligneous 

 parts of the tree. It is, indeed, an excellent salve for the 

 wounds produced by the amputation of branches ; though, 

 for this purpose, I deem Forsyth's composition of cow- 

 dung and ashes preferable, in such situations, as admit of its 

 being easily attended to, and renewed. 



