NEPTICULA PLAGICOLELLA. 273 



Original description. — Nepticula plagicolella, n. sp. Alis anticis 

 nitidis fuscis, postice purpureo-tinctis, fascia fere recta pone medium 

 nitida, albida, parum argentea ; capillis ferrugineis. Exp. al. 2 lin. 

 Head and face reddish-yellow. Palpi whitish. Antennae fuscous, 

 basal joint whitish. Anterior wings shining fuscous, with a purple 

 tinge, which begins before the middle of the wing ; beyond the middle 

 is a nearly straight, shining, whitish, rather silvery fascia ; cilia 

 fuscous. Posterior wings pale grey, with pale grey cilia. Appears in 

 May and August, but I believe not hitherto met with in the perfect 

 state. The larva mines in the leaves of sloe in autumn and July, 

 making large whitish blotches ; in some places it is exceedingly 

 plentiful ; the cocoon is rather flat (Stainton, Insecta Britannica, 

 pp. 303-304). 



Imago. — Head reddish. Anterior wings 4-5 mm. ; shining fuscous, 

 with a purple tinge nearly from the base ; beyond the middle is a 

 nearly straight, shining, rather silvery, transverse fascia ; cilia dark 

 blackish-grey. Posterior wings and cilia pale grey. 



Comparison of N. plagicolella with N. betulicola, etc. — 

 This species is nearer to A T . betulicola than to any other of the species 

 already dealt with. In the latter the head-hairs are paler, the cilia of 

 the fore-wings lighter and purer grey, the transverse band less shining 

 and placed beyond the centre, at least two-thirds of the length of the 

 wing from the base, whilst in X. betulicola the transverse band is 

 nearer the centre of the wing. Its resemblance also to N. microtheri- 

 ella may lead to confusion, but this species is smaller, the head-bairs 

 . are not reddish, but ochreous ; the fore-wings and the band, too, are 

 less shining, the latter is silvery and placed more obliquely. It also 

 resembles X. centifoliella ; the head of the rose-miner, however, is 

 lighter, more yellowish, and it is somewhat broader-winged, whilst the 

 colour of the fore-wings is less dark, and the band less shining, in those 

 specimens which most resemble lY. ■plagicolella in breadth and form of 

 wing. The transverse band of X. centifoliella, too, is probably placed 

 somewhat further beyond the middle of the wing than in X. plagicolella, 

 and, lastly, the fringes are brown-black, darker than in X. plagicolella, 

 yet, it must be confessed that the separation of the two species does 

 not appear to me to be easy (Frey). Stainton notes that X. plagicolella 

 "belongs to that section of the genus in which there is a single brilliantly 

 metallic fascia on the anterior wings ; the whitish silvery colour and 

 the nearly straight direction of the fascia, at once separate it from 

 most of the allied species, and the reddish-yellow colour of the head 

 distinguishes it easily from the fuscous-headed X. acetosae, and the 

 black-headed A r . prunetorum." 



Egg-laying. — The egg is laid on the upper side of a sloe leaf. 



Mine. — When newly-hatched, the larva commences a long and 

 extremely slender mine, which, being filled with blackish excrement, 

 appears almost as a crooked black line ; but, after continuing in this 

 linear track for some distance, the larva mines a complete blotch of an 

 irregular oval figure, and of a pale greenish-white colour ; in the 

 Central portion of this blotch the black excrement forms a little heap ; 

 not unfrequently two larvae, mining in the same leaf, will meet at the 

 blotched portion of the mine, and have a larger blotch in common. 

 The larva leaves its mine to spin its cocoon (Stainton). Frey writes : 

 " Die Mine, in welcher zuweilen zwei Raupchen angetroffen werden, 



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