﻿NOTES ON AGROTIS ASHWORTHII. 7 



velvety black ; a bright red shining head and red-brown prolegs 

 stand out in strong contrast, giving the caterpillar a decidedly 

 distingue aspect, which at once marks it out from the common 

 herd of Noctuse. 



The indescribably beautiful dove-colour of the fore wings of 

 the perfect insect has already been alluded to. As in so many 

 other living things, this ebbs away sadly with the life of the 

 insect. Across the wings run three wavy dark lines ; between 

 the second and third is a rich brown shade, very much enlarged 

 in the female, almost absent in the male ; within this patch of 

 colour the orbicular and reniform are more or less conspicuous, 

 according to the intensity of the shade; the hind wings are 

 smoky grey ; and the head, thorax, and body pale blue grey, like 

 the fore wings. Though simple and quiet in colouring, the 

 imago of Agrotis ashivorthii, like its larva, is at once beautiful 

 and striking, and cannot possibly be mistaken for any other 

 British species. 



Now in writing thus of the life- history of A. ashworthii, the 

 question naturally suggests itself, How comes it that this parti- 

 cular Noctua is confined to so limited a habitat, and is, so far, 

 unknown to exist elsewhere ? 



The Entomological fauna of the greater part of Europe has 

 now been pretty thoroughly investigated, and much collecting 

 has been done in various other parts of the world, yet A. ash- 

 worthii has never yet been discovered in any other locality. Why 

 is it that the insect has never strayed from its native Welsh 

 mountains, while most species of these temperate climes have so 

 wide a range of habitat ? How long has it existed and nourished 

 there, and where did it originally come from, leaving apparently 

 no trace of its kindred behind it ? Who can tell ? 



Its food-plant is no rare and local herb ; the wild thyme, rock 

 cistus, and other plants upon which it thrives, are common in 

 many other places. The geological formation which it prefers is 

 a limestone found in many parts of Great Britain, as well as on 

 the Continent of Europe and elsewhere. Its habitat is neither 

 alpine, insular, nor peculiar as to climate or otherwise ; and yet 

 our insect seems debarred, in some mysterious and extraordinary 

 way, from straying abroad from its own particular adopted home. 

 It cannot, of course, have existed there always, but must have 

 travelled westwards with one of the great waves of life which 

 invaded these islands from the Continent some time after the 

 close of the last glacial epoch. Still, impelled by some curious 

 impulse, it has journeyed straight to its present mountain home, 

 leaving no colonies in similar situations behind it in its course, 

 nor, apparently, any survivors in the original cradle of its race. 



The species of Agrotis which it most resembles is the conti- 

 nental A. candelarum (Staud.). This somewhat rare insect has a 



