INDIRECT INJURIES CAUSED BY INSECTS'. 199 



chinks and 'rugosities of the bark, where it increases 

 abundantly, and by constantly drawing off the sap causes 

 ultimately the destruction of the tree. Whence this 

 pest was first introduced is not certainly known. Sir 

 Joseph Banks traced its origin to a nursery in Sloane 

 Street ; and at first he was led to conclude that it had 

 been imported with some apple-trees from France. On 

 writing, however, to gardeners in that country, he found 

 it to be wholly unknown there. It was therefore, if not 

 a native insect, most probably derived from North Ame- 

 rica, from whence apple-trees had also been imported by 

 the proprietor of that nursery. Whatever its origin, it 

 spread rapidly. At first it was confined to the vicinity 

 of the metropolis, where it destroyed thousands of trees. 

 But it has now found its way into other parts of the king- 

 dom, particularly into the cyder counties; and in 1810 

 so many perished from it in Gloucestershire, that, if 

 some mode of destroying it were not discovered, it was 

 feared the making of cyder must be abandoned. This 

 valuable discovery, it is said, has since been made ; the 

 application of the spirit of tar to the bark being recom- 

 mended as effectual a . Sir Joseph Banks long ago ex- 

 tirpated it from his own apple-trees, by the simple me- 

 thod of taking off all the rugged and dead old bark, and 

 then scrubbing the trunk and branches with a hard 

 brush. 



a This Aphis is evidently the insect described in Bligcr's Mqgazrn, 

 i. 450. under the name of J. lanigcra, as having done great injur} to 

 the apple-trees in the neighbourhood of Bremen in 1801. That it is 

 an Aphis and no Coccus is clear from its oral rostrum and the wings 

 of the male, of which Sir Joseph Banks possesses an admirable draw- 

 ing by Mr. Bauer. On this Aphis sec Forsyth, 265 ■ Monthly Mag. 

 xxxii. 320; and also for August 1811, ; and Sir Joseph. Banks in the 

 Horticultural Society's Transaction?, ii. 162. 



