268 THE ENTOMOLOGIST. 
The larva generally holds itself erect at an angle with the food- 
stalk, with the first four segments thrown forward. It feeds to my 
knowledge on oak, elm, plum, and rose. I have never seen it on 
larch; but it feeds probably on many other trees, and takes eight 
or nine weeks to come to maturity. 
The pupa.—The larva simply buries in the ground and spins 
no cocoon, and changes to a pupa of the common chestnut-colour, 
rather pale, especially on the wing-cases. 
The imago.—It would be impossible, if it were not needless, 
to describe the varieties and shades of difference in this stage. 
Hardly two are alike, and if there is a second species it certainly 
cannot be distinguished in the imago. I will, however, notice a 
few leading types. 1. Ground colour bone-white, finely dusted 
with grey, the transverse lines being visible only on the wing-rays 
as black points. 2. The same, but well marked with strong, 
black, transverse lines. 8. Grey-brown, much dusted with 
darker, and slightly tinged with ochreous. 4. Sooty black, a few 
srey scales on the sides of the thorax, and a white line beyond the 
invisible subterminal line. 5. Ochreous grey, a band of warm 
brown or ferruginous colour following the black transverse lines. 
(I believe this is the original biwudularia, so named from the two 
conspicuous bars or waves formed by the transverse line and its 
accompanying band or wave of warm colour). 6. Specimens 
from Perth are larger and better marked than any of the 
preceding, the ferruginous band becoming umber-brown. 
The moths generally emerge in May; but I have seen it a 
month earlier, and received it alive this year (a backward year) 
from Mr. Harrison, of Barnsley, on June 25th. In the South of 
England a remarkable form or “subspecies ” of this moth appears 
on the wing in March, and produces a second brood at the end of 
July. The question, Is this a distinct species? will only be 
solved finally when we know more of the egg and larva of this 
double-brooded insect. It may prove to be a distinct species ; 
but if so, it will not be to the credit of south-country entomo- 
logists if the doubt is allowed to remain much longer. If, on the 
other hand, it be not a distinct species, we have to observe these 
two remarkable facts, viz., that in the South of England the first 
brood continues to fly from the beginning of March till the end 
of May (a most unusual duration), and also that a double- 
brooded variety of the species exists side by side with the single- 
