Apide Inscds. 465 



At the meeting of the Entomological Society on the 7th of 

 August, 1838, Mr. Spence called the attention of the members 

 to the circumstances which he had observed connected with the 

 destruction of the apple crop during the past spring; and sug- 

 gested, without, indeed, stating that it was directly attributable 

 thereto, that the plant lice (aphides) might be the chief cause of 

 the mischief, as great numbers of one of the species of these 

 insects had been observed upon the young shooting leaves which 

 enveloped the blossom buds previously to the bursting forth of the 

 latter ; the effect of which would be, that these leaves would be 

 stopped in their growth ; and, as their agency in the developement 

 of the blossom bud is necessarily very great, the latter would be 

 so much weakened as to be unable to burst forth, Mr. Spence, 

 however, deemed it advisable to direct attention more precisely 

 than had hitherto been done to the circumstances connected with 

 the flowering of the apple, so that the real cause of the mischief 

 might be detected. 



At Hammersmith, a great failing of the apples has taken place, 

 some of our trees not having a single apple left on them at the 

 present time. This has been produced in two different modes. 

 The apples blossomed beautifully; but no sooner was the blossom 

 gone, than the young apple, with its long stem, fell lo the ground ; 

 and, in the case of those which did attain some size, they were 

 attacked, when about one fourth of their full size, by a hymenop- 

 terous insect, of the economy of which no account has hitherto 

 been given, neither has it been supposed to feed upon this fruit. 

 When my observations upon it are sufficiently perfected, I hope 

 to lay it before the readers of this Magazine, as a very interesting 

 article in my series. As far as my own observations upon the 

 earlier state of the flowers and leaves extend, I did not notice 

 any aphides ; and I cannot but attribute the falling of the very 

 young fruit to causes distinct from the attacks of insects, as I 

 could observe no traces of their action in the multitudes of fallen 

 embryo apples, or upon the stems from which they had fallen. 

 I have shown at fg. 95. B the state of the fruit as it almost 

 universally appeared when fallen ; and I noticed that, at this time, 

 the slio-htest touch was sufficient to cause the vouncj fruit to 

 drop from the twig. Two causes have, indeed, been suggested 

 for this, independently of the work of insects ; namely, the action 

 of cold or rain, which, as in the last long cold spring, would 

 either have the effect of so much weakening the stamens as to 

 render them unable to burst, or, supposing them actually to have 

 burst, the rain would wash the pollen away, and so prevent 

 the impregnation of the fruit. This is not a novel idea, being, I 

 believe, alread}' assigned in works as one of the causes of the 

 failure of the setting of the fruit : the other cause, suggested by 

 Mr. Ingpen, was, that, as last year was a very abundant ajiple 



Vol. XIV. — No. 103. h h 



