247 



MELANISM IN LONDON LEPIDOPTERA. 



Bv J. AV. TuTT, F.E.S. 



A NOTE, written b}'' my friend Mr. T. D. A. Cockerell 

 (Entom. 00), relating to a statement (Entom. xx. 202), to the 

 effect that there was no London melanism, has produced a few 

 communications about the matter, which I deem very unsatis- 

 factory, considering the number of London lepidopterists and 

 the sweeping assertion made. All our correspondents, so far, 

 who have given instances of London melanism, have confined 

 their attacks to one little species, Miana strlg'dis, which is 

 frequently melanic in all parts of the country, and generally so 

 in certain of the Northern and Midland counties of England. 



There is no doubt that the assertion about London melanism 

 was made on altogether insufficient data. In one group alone, 

 the Noctuse, a large percentage of cases of melanism or partial 

 melanism occur, the following, among others, having come under 

 my own notice : — 



Acronycta psi var. svffusa* The type does not occur in 

 London ; the dark variety only is found. 



Leucania comma var. siiffusa.* The forms occurring in the 

 Greenwich district ai^e altogether darker than more northern 

 specimens. — L. straminea var. nlgrostriata* A small percentage 

 of London specimens are thickly sprinkled with black scales 

 between the nervures. — L. impura var. fuligosina* Haw. This 

 is the common form of impura in London, where the pale type is 

 almost unknown. — L. imllens var. siiffasa,* St. This variety 

 occurs occasionally in the London reed-beds with the type, the 

 spaces between the nervures being much suffused with dark 

 scales. 



ITydracia mlcacca var. hriinnea. Some London varieties, 

 which I have bred from roots of dock, are of a rich brown 

 colour. 



Xylophasia mo)ioglyplia. Deep brown varieties occur fre- 

 quently on the marshes. 



Mamcstra ahjecta. Only the dark var. nigricans is taken in 

 TiOndon, so far as I know. I have never captured the variegated 



* Vide Eiitom., vol. xxi. Series of papcid ou " Yariulioa of Noctua:."' 



