Transactions of the London Horticultural Society, 409 



have been informed that it abounded in the Royal Gardens at Kew in the last 

 summer. The moth appears in the end of May and the beginning of June ; 

 and it is readily distinguished by the silvery whiteness of its. wings, which are 

 tipped lightly with brown, and by its small size, its length scarcely exceeding 

 a single line. It is an extremely pretty little insect, and possesses so much 

 activity, that it is difficult to obtain a living specimen of it. It probably 

 deposits its eggs, or, perhaps, more properly, its spawn, upon the under 

 surfaces of the leaves ; and the larvae, having there penetrated through the 

 epidermis, feed upon the internal parenchymatous matter of the leaf. Brown 

 and lifeless circular spots in consequence appear upon the leaves, such as an 

 excess of heat would occasion ; and I have known several gardeners who 

 have supposed it to be caused by solar action. These lifeless spots enclose 

 the larvEe of the moth above mentioned, which do not exceed a line in length. 

 Whenever the leaves of a pear tree contain many of these, the fruit does not 

 acquire nearly its natural size, and it ripens without acquiring either sweetness 

 or flavour. 



" This insect is an old inhabitant of our gardens i I first observed it half a 

 century ago, but it appears latterly to have become much more abundant. It 

 greatly prefers some varieties of pears to others ; the chaumontel appears, 

 amongst the varieties in my garden, its favourite, and the glout morceau that 

 which it likes least. The moth is, I believe, but little known ; for Mr. 

 Curtis, who was so kind as to give me the name of it, did not possess a 

 specimen till he received one from me. My pear trees had sustained, during 

 many successive years, so much injury from the depredation of this insect, 

 and their fruit had in consequence become so defective in freshness and 

 flavour, that I resolved to uproot the whole of them, if I failed to succeed 

 in destroying or driving away the insects : but in the last summer I had the 

 good fortune to obtain perfect success in driving them away, by the means 

 which I proceed to describe. 



" Early in the spring of the year, when the blossom buds of my pear trees 

 were about the size of large peas, water, which held in suspension a mixture 

 of lime and flower of sulphur and soot, in about equal portions, was thrown 

 by an engine over the pear trees and the surface of the wall to which thev 

 were trained. I applied this mixture because I had observed, as I have stated 

 in a former communication, that it had apparently prevented the appearance 

 of blistered leaves upon my peach and nectarine trees, though by what mode 

 of operation I was then, as I still am, wholly at a loss to conjecture : but 

 since the first application of it, I have not seen a single blistered leaf upon 

 any tree to which it was applied. I, of course, distinguish blistered leaves 

 from such as have been made to contract by the bite of the aphis, 



" The moths appeared as abundant as in the preceding year ; and I then 

 caused my trees to be washed once in every week during a month, after I 

 witnessed the first appearance of the moth, with a weak infusion of tobacco 

 in water : this mode of treatment proved successful, and the foliage of my 

 pear trees, and some plum trees contiguous, escaped all injury. The moths 

 were, however, only driven away ; for the leaves of two pear trees which 

 grew at some distance were almost wholly destroyed, and the foliage of the 

 medlar and cherry trees in the vicinity sustained a good deal of injury from 

 them. Nearly all the leaves which contained any of the larvae were collected 

 and burned, and comparatively very few of the larvae escaped ; and I do not 

 at all doubt but that, by adopting the same measures next year, I shall succeed 

 in securing my pears from future injury. 



" There is another species of insect which frequently injures the pear tree, 

 whose depredations are less visible, and consequently less known to gar- 

 deners. It has greatly the appearance of an aphis, and is found dispersed 

 over the under surface of the leaves whilst young, and is always immersed in 

 a globule of honey ; in their more mature state these insects are found con- 

 gregated round the base of the buds, particularly those which are calculated 



1840. August, e e 



