NEPTICULA ARGYR0PE2A. 329 



Nolcken describes the larva as " translucent pale yellow, at times 

 somewhat darker-coloured, but frequently colourless ; the alimentary 

 canal green (when empty it is only visible as a weak brownish or 

 reddish shade) ; the anal flap margined by a fine dark line on either 

 side.; the head transparent, pale brown, with darker brown sides, 

 yellow-brown mouth-parts and darker sutures ; the forehead suture 

 anteriorly convex, thick, dark brown, as also are two divergent curved 

 lines concave to one another, bounding the clypeus. Generally the 

 younger larva? are more deeply coloured, often amber-yellow with a 

 greenish tinge, owing to the green intestinal canal. The anterior 

 segments bear, ventrally, lozenge- shaped spots, which commence in a 

 large brown subcutaneous throat-spot, and are more compressed on 

 segments nearest head ; these are very small and inconspicuous in 

 young larva?." Wood notes the larva as " mining with the venter 

 uppermost," and it has the habit, Nolcken says, of retiring into the 

 mined petiole to moult. The full-fed larvae remain some time in the 

 mine (they have been found in leaves covered with snow), and when 

 they do spin their cocoons they do not change to pupae until the spring. 



Cocoon. — The cocoons examined (9) average almost 3 mm. in 

 length, and 2-2 mm. in width. The cocoon is almost oval in outline, 

 one end, however, being decidedly broader than its nadir, very distinctly 

 domed both above and below the rim, the latter being composed of 

 a mass of loose, flossy silk. The cocoon proper is closely woven, of a 

 dark drab (inclining to greenish or brownish in different cocoons) 

 colour, loosely invested in a thick covering of shining, flossy silk, 

 which is somewhat paler than the inner part of the cocoon. The 

 empty pupa-case, which projects from the broader end of the cocoon, 

 is quite transparent and colourless, the abdominal segments being pro- 

 vided dorsally with a broad belt of shiny brown hooks. [Described 

 from cocoons sent by Dr. Wood, July 12th, 1898.] The larva forms, 

 on the ground, a flat, pale brown and rather woolly cocoon, from 

 which the pupa protrudes just before the escape of the imago (Vaughan). 



Food-plants. — Populus tremula. Also P. alba (Sorhagen). 



Time of appearance. — The species is single-brooded, appearing in 

 May and June, from larva? that feed up the previous July-November, 

 and do not pupate until a short time before the emergence of the 

 imago. Vaughan reared imagines in March-April, 1859, from larva? 

 found the previous October and November, at Bristol. Stainton 

 obtained imagines at Beckenham from May 20th-25th, 1851, 

 and on June 9th, 1849, at Woodhead Moors, nr. Sheffield ; whilst 

 Threlfall caught imagines at Witherslack on May 14th, 1875 ; he 

 also bred imagines from larva? obtained the previous October, from 

 May 12th-22nd. Mann records it at the beginning of June, 1846, at 

 Pratovecchio ; and Evans captured imagines at West Wemyss on 

 May 30th, 1895. Nolcken records larvae from September 20th, 

 throughout October and into November, annually, at Pichtendahl, 

 most easily found in the fallen leaves, the mined area remaining 

 green. 



Localities. — Durham: Darlington (Sang). Edinburgh: Eavelrig Bog 

 (Logan). Fife : West Wemyss (Evans). Gloucester : Bristol (Vaughan). Hants: 

 New Forest (Bankes). Hereford : Tarrington (Wood). Kent : Beckenham 

 (Stainton). Lancashire: Grange (Hodgkinson). Sussex: Abbott's Wood (Fletcher). 

 Westmorland: Witherslack (Threlfall). Yorks : Woodhead Moors (Stainton), 

 Sheffield (Wilson), Scarborough (Meek). 



