13 



Notes on Hepialus Humuli and its Shetland Forms. 



By Robert Adkin, F.E.S. Read April \^th, 1910. 



Attemtion appears to have been first called to the remarkable 

 forms of Hepialus hiimuli, that are now so well known to occur in 

 Shetland, by Edward Newman, who, in a note published in February, 

 1865, under the heading of " Singular Geographical Race of Hepialus 

 humuli" refers to a series exhibited at the January meeting of the 

 Entomological Society by Mr. Bond, and subsequently placed in 

 the British Museum Collection. Newman concludes his note with 

 the remark, " Should these specimens prove anything more than a 

 geographical race and be received as a species, I would propose for 

 them the name of Hepialus thulensis" ("Entom.," vol. ii, p. 162). 



In the following month, W. D. Crotch, who appears to have been 

 a frequent visitor to Shetland, wrote under the heading '^Hepialus 

 humuli, var. thulensis" saying that four years previously he had taken 

 a long series of these forms in Unst (Shetland), and tried at the 

 time to create some little interest in them. He then goes on to say, 

 "Such geographical races are of great interest, only I should be very 

 sorry to see new names affixed when the original names marked var. 

 would prevent undue multiplication of species, and indicate both a 

 principle and a fact. The insect in question would thus stand as 

 H. humuli, var. thulejisis" ("Entom.," vol. ii, p. 176). 



Dr. Knaggs, in the "Annual" for 1865, refers to the museum series, 

 and is "inclined to consider them a climatic variety or race of our 

 common H. humuli" ("Ent. Ann.," 1865, p. 98). 



These notes appear to have had the desired effect of creating an 

 interest in the Shetland forms of H. humuli, and further, a desire on 

 the part of some entomologists to show that similar forms were to be 

 found elsewhere ; tlius, in the following February J. O. Westwood 

 published the translation of a letter received from M. Snellen von 

 Vollenhoven, in which he says that " H. humuli was very abundant 

 near the little lakes of Rotterdam. M. P. Snellen found near those 

 waters a very interesting male specimen with female coloration on 

 the upper side" ("Entom.," vol. iii, p. 27). Then in March, Albert 

 Miiller, in a note under the heading of H. humuli, var. thulensis, 

 draws attention to an article in the " Entomological Magazine," 

 vol. i, p. 42 (published 1832), where George Wailes in "A Catalogue 

 of a few Insects found at Castle Eden Dean," says he has taken 

 " specimens of H. humulus, with the anterior wings of a yellow tinge ; 

 and my friend Mr. Hewitson has shown me similar specimens, 

 captured in the Orkneys this season, which have very distinct 



