67 
tifiuious, that in two or three weeks "the whole 
tj-ee is liable to be very numerously infested by 
their offspring'. 
This species, like the rest of its genus, is 
the progenitor of several generations in one year*. 
At different periods, they become furnished with 
wings, and emigrate to different parts of the gar- 
den, and sometimes to a mueh greater distance. 
They appear seldom to attack any other tree but 
the Plum or Plum stocks. Their favourite prey 
is the leaves and twig ends of the most luxuriant 
young branches, and not always the weakest 
branches, as we find commonly asserted, a natural 
mistake made by indolent observers, for these 
animals immediately not only cheek the progress 
of the branches, but produee inability or weak- 
ness, but even completely destroy the latter 
growth of the branches, dirty and destroy the 
beauty of the whole tree, eiipple and besmear 
the fruit, so that, for want of beauty and flavour, 
it is rendered nearly useless. Even whole crops 
have, in some gardens, not been worth gathering. 
For their Destruction. — Should the 
summer pruning and nailing not be done, it 
would be of greater advantage in saving the mix- 
ture, and rendering a better opportunity for the 
performance, to have them done before the appli- 
cation of the Mixture. At the summer season 
the Mixture (No. 1) may be applied; but as the 
fruit of some kind, such as the Orlean, Precocede 
de Toms, and many others, is liable ^to crack in 
