tlie Diamond-back Moth. 
599 
from Yorkshire, in one case near Northallerton, in the tvro others at 
the same localities as in the previous year, namely, near Market 
Weighton, and Holme Hall, York. Attack was also reported, and 
as very bad, near Inverurie, Aberdeenshire, N.B. 
In the present year the infestation has been more or less present 
along the eastern coast, or eastern side of the country from Dover 
up to Aberdeen, and I have also observations of its presence near 
Fishguard, Pembrokeshire, near Newport, Salop, and near Lytham, 
Lancashire ; and also in the island of Islay, on the West of Scot- 
land ; and from general information it may reasonably be presumed 
to be present at many other places, including localities in the west 
and north of Scotland. Later on, that is about August 1-1, the 
presence of the infestation was announced in Ireland, especially 
along the eastern coast, and I had opportunity of identifying speci- 
mens from Dunleer, co. Louth. 
In this country, though it is rare to have bad attacks, yet the 
insect is common and abundant in many places during the summer. 
Elsewhere it is widely distributed — being injurious even in Cape 
Colony. Nearer home its presence as a Continental pest may 
prove an important consideration with regard to transmission of 
wind-borne infestation. That moth attack can be so brought is 
well known, as, to give a single instance, in the case of the silver Y 
moth, the Flusia gamma, which crossed over from the Continent in 
the summer of 1879 ; but whilst in this case, from the size of the 
moths, the flocks could not escape observation, with the little 
diamond-backs there is no such necessity of observance, and their 
appearance was little thought of untU a reason for the vast appear- 
ance of caterpillars came under consideration. 
Description of the Motu. 
The size of these moths is only about, or rather under, two- 
thirds of an inch in the spread of the wings, and to ordinary obser- 
vation when at rest they appear as brownish-grey moth.s, about the 
size of furniture moths, but long and narrow in shape. When at 
rest, and the upper wings laid along the back, witli the edges meet- 
ing, the pale patterns along these edges form diamond-shaped marks, 
whence the English name " diamond-back moth " ; if seen side- 
ways, the curved up extremity of the wings as shown at 3 and 1 in 
the figure on page 597 is very strikmg. 
On minute examination it will be found that the front wings 
are long and narrow ; greyish brown, darker towards the centre, 
but marked with some small brown spots in front, a rather broad 
whitish or oclireous-grey band runs along the hinder margin, with 
three rounded projections on its front edge ; this band is usually 
spotted with very small dark points, and in some specimens it is 
considerably obscured by the ground colour on the hinder margin, 
leaving the three projecting parts alone conspicuous. The hind 
wings are narrow and pointed at the apex, have a long fringe, and 
are of a pale ashy-grey colour. The body and legs are brownish grey, 
