4^^ AND ^^/^ 



JOURNAL OF VARIATION. 



No. 2. Vol IV. February 15th, 1893. 



With Notes on Variation, Habits and Affinities.* 

 By J. W. TUTT, F.E.S. 



The genus Xanth'a and the species we usually ally with it, 

 probably attract more attention from the collector than that of any 

 other group of the Nocture. Their colours are attractive, and in our 

 cabinet drawers immediately arrest the attention of anyone looking at 

 them. The colour is in all the species of a yellow or orange shade, and 

 it is not difficult to understand that their appearance in the imago state 

 at the beginning of, or, in fact, well into the autumn months, and their 

 habit of clinging to the leaves of the trees, or to the gi'asses and low 

 plants at the base of the trees or bushes on which the larvse feed, make 

 these shades of colour especially useful as a protection when simulating 

 the yellow leaves which at that time of the year hang so thickly in the 

 spiders' webs, on the grass, etc. ; and more than one of the food-plants 

 of these species (e.g. sallow and lime) are particularly noticeable for 

 the bright yellow tint of the falling and newly-fallen leaves in the 

 autumn. The darker lines and blotches on the wings aid the simulation 

 still more strongly, and the exact resemblance which Hoporina croceago, 

 a supposed near ally to Xanthia, bears to the dead oak-leaf, into which 

 it usually appears to crawl to spend the winter months, is particularly 

 striking, and if we consider the gi'eat abundance of both X. fulvago 

 and A', flavago, compared with the few specimens one meets at rest 

 during the day, the completeness of their protective resemblance can 

 be readily understood. Mr. Holland writes : — " The natural hiding- 

 place of fulvago and flavago is among the long grass and herbage 

 growing near the sallows. In damp woods they are especially plenti- 

 ful, and I often see them at dusk, struggling out of the tangled 

 stuff beneath the sallows, and crawling up to the tops of the long 

 grasses, — hundreds of them, on some favourable nights, — and they 

 may be readily looked over and boxed. They are not, however, 

 always in the same humour, and on some nights they fly about a 

 great deal. A few moths, odd ones, fall from the sallow-bushes 

 into the Bignell during the day, but not many rest there, and perhaps 

 those found are moths which have just emerged and dried their 



* Eead before the City of London Entomological Society, February 7th, 1893. 



