THE INJURIOUS SCALE INSECTS AND MEALY BUGS, &c. 241 
Hawthokn and Apple Lecanium 
{Lecanium genevense, Targioni-Tozzetti). (Fig. 104.) 
I have never met with this insect in sufficient numbers upon Apple 
to claim it as injurious to that plant. But its presence upon Hawthorn 
is very different. I have not infrequently found it in such vast colonies 
as to kill large patches of a Hawthorn hedgerow ; and I am sure a glance 
at the photograph (fig. 104) will confirm my statement. 
The number of eggs laid by a single female average between 2,000 
and 3,000. Fortunately it is single-brooded, like all other indigenous 
species, otherwise it would, if unmolested, very soon cause ruin to every- 
thing it attacked. 
The eggs are laid about August ; the young, escaping shortly after- 
wards, pass the winter without changing. In spring they rapidly 
develop, and in May have attained their full size. The females are then 
large gravid insects, of various shades of mahogany red, and often possess 
transverse whitish zebra-like markings. At this stage the bright red 
males make their appearance from their little glassy-white scales, which 
may be found fixed to the branches alongside the females. The vast 
difference between the form and size of the sexes in coccids is a very 
marked feature ; but it cannot well be more so than in this species, in 
which the female is from fifty to one hundred times the size and weight 
of her partner. This species is much subject to the attacks of internal 
parasitic larvae of small Hymenopterous insects allied to the bees and 
wasps. They escape as perfect flies by cutting small circular perfora- 
tions in the derm of their host, of which there is some trace in the 
illustration. 
Another remarkable coccid belonging to this genus is also found upon 
the Hawthorn, but it is rare, and has only been met with in a few 
isolated localities. This is the Lecanium hituberculatum, also described 
by Professor Targioni-Tozzetti. It can generally be recognised from the 
preceding species by the possession of two conspicuous tubercles arising 
from the back of the insect ; and it may also be distinguished by the 
permanency of the coloured bands or markings so characteristie of the 
species. As an example of protective resemblance it is very fine, and 
generally difficult to detect. 
The Rose harbours a brown scale {Lecanium rosce) which is fre- 
quently injurious ; but it is so closely allied to the L. persicce of the 
Peach that I am at present unable to separate them without entering 
into very minute detail. 
Brown Currant Scale 
(Lecanium coryli, Linna3us=Iy. jibis, Fitch). 
This species very closely resembles the Peach Scale, but is much 
smaller and of a paler colour, and feeds upon a greater variety of plants, 
which include the Currant, Gooseberry, Raspberry, and Cotoneaster, and 
it has also been found on certain conifers. 
Like L. jpersicce, the males are also unknown — a most remarkable 
fact, since the species has been more or less under observation from the 
