296 BRITISH LEPIDOPTERA. 



Distribution. — Eussia : Alten in Lapland (Staudinger teste Durrant), 

 Finland (Staudinger and Wocke). Scandinavia : Bossekop, Finmark 

 (Wocke). 



nepticula confusella, Walsm. and Wood. 



Synonymy. — Confusella, Walsingham and Wood, " Ent. Mo. Mag.," xxx., 

 pp. 272-273 (1894) ; Meyrick, " Handbook," etc., p. 724 (1895). 



Original description. — Antennae in the $ long (reaching to the 

 fascia when laid back at rest), shorter in the ? , cinereous ; eyecaps 

 whitish. Head amber-yellow. Thorax brownish-cinereous. Fore- 

 wings brownish-cinereous, with a slight purplish lustre in a strong 

 light, especially towards the apex ; a broad, ill-defined, whitish fascia 

 at two-thirds of the wing length, scarcely oblique, but slightly inclining 

 outwards from the costal margin to before the anal angle, somewhat 

 narrower in the middle than on the costal and dorsal margins ; cilia 

 brownish-grey, paler on their outer half, and about the anal angle. 

 Hind-wings greyish, cilia with a slightly browner tinge. Abdo- 

 men brownish-cinereous. Posterior legs pale cinereous. Exp. 

 alar. 4-5-6 mm. Emerges beginning of May (in confinement) " (Wal- 

 singham, Ent. Mo. May., xxx., pp. 272-273). A life-history by Wood 

 follows. 



Imago. — Head yellowish. Anterior wings 4-5-6 mm. ; brownish- 

 grey, with a slight purplish tint towards the apex ; a broad, ill-defined 

 whitish fascia, slightly inclined outwards, beyond the middle ; cilia 

 brownish-grey, paler on their outer half. Posterior wings and cilia 

 greyish. [This and the preceding species may belong to Group V.] 



Comparison of N. confusella with N. lapponica. — The species 

 are very close in the imaginal state, but N. confusella may be dis- 

 tinguished by its darker colour and more distinct fascia. The larvae 

 are, however, distinct enough. Thus, instead of greenish-white, the 

 larva of N. lapponica is yellow, with a black head and black pro- 

 thoracic plate, the latter much obscuring the brown cephalic ganglia. 

 The mine, also, of N. lapponica is quite distinct ; in the early part the 

 frass is green, coiled, and quite fills the bore ; afterwards, and con- 

 currently with the last moult, it gets collected into a central thread, 

 and changes from green to black, becoming from this point a facsimile 

 of the mine of the other (Wood). 



Egg-laying. — The egg is laid on the underside of a birch leaf. 



Mine. — The mine is large and angular, and consists of a long 

 gallery of moderate width, whose usual course is to follow a rib for some 

 distance, and then to turn off at a tangent till another is reached, 

 which in its turn is pursued ; the mine is never contorted, and even at 

 its very commencement the delicate hair-like gallery stretches straight 

 away at once from the site of the egg. The frass is black, and forms 

 a central thread throughout, there is no coiling in the middle portion 

 of the mine, and a free margin borders its track in all three portions, 

 so that the character of the mine is uniform from beginning to end. 



Larva. — The larva is greenish-white in colour, the head very pale 

 brown ; immediately behind the latter is a pair of dark conspicuous 

 spots (the cephalic ganglia). As it burrows in the leaves of birch with 

 the back uppermost, it shows distinctly the cephalic ganglia, which are 

 dark, and markedly more conspicuous than the head. No trace of the 

 ventral cord is distinguishable so long as the larva remains in situ. 



Cocoon. — The cocoons, examined (6) average about 2*5 mm. in 



