December, isn.'i. 273 



REMARKS ON SCOPARIA BASISTRIGALIS, Knaogs. 

 BY B. A. BOWER, F.E.S. 



A comparatively short series of the above species, which I 

 exhibited at a Meeting of the Entomological Society of Loudon held 

 last March, having apparently interested several of the Lepidopterists 

 present, it may be as well to give a few remarks upon the insect. 



The shape of this species will always distinguish it from nmbigiialis, 

 its fore-wings though narrow close to the base, being decidedly broader 

 than in that species, with a greatly arched costa — especially so in the 

 females. And again, the time of its occurring would tend to prove it 

 distinct, as although there is actually no definite period between its 

 emergence and the disappearance of ainbigualis, the latter has become 

 greatly diminished in numbers and in a dilapidated condition, before 

 hasistrigalis puts in an appearance. Added to which any one having 

 seen the species in nature cannot but have been struck with the 

 peculiarly robust look of the insect— due to the width of the united 

 fore-wings — when at rest on palings or tree-trunks, in which position 

 some of the aberrations assimilate in a wonderful manner with their 

 surroundings. For instance, an exceptionally dark specimen on a 

 tarred fence, or a silvery-grey one on a lichen-covered tree-trunk. 



The moths are not uncommon in one or two woods in Kent, but 

 in these are restricted to a very small area, and even then show a 

 marked partiality for certain trees, though to all appearances these are 

 similar to the rest in every respect. 



Hitherto efforts to obtain larvae of this moth have been fruitless 

 and I think I have proved it not to be a moss-feeder, as the 

 experiment of placing a number of females in pots of growing moss, 

 resulted in complete failure ; whereas S. cratcegalis and S. mercurella 

 so treated, breed freely. 



I know it is the opinion of some Entomologists that this is only 

 a local form of ambigualis, and that the variation is solely due to more 

 succulent food-plant or damp situation. Now this surmise might 

 hold good in the case of the exceptionally dark specimens, but 

 unfortunately for this reasoning, there are also the light ones 

 occurring with them to be taken into account, and indeed the situation 

 where I find it most commonly is abnormally dry, as may readily be 

 conceived when it is stated that the district is a sandy one, with a 

 sub-soil of chalk. 



Appended are brief descriptions of a few of the most pronounced 

 aberrations in my cabinet, though they give but a faint idea of the 

 great range of variation exhibited in the lengthy series of about fil'ty 



