192 BRITISH LEPIDOPTERA. 



COMPARISON OF N. PYGM^ELLA WITH ITS ALLIES. JY. pi/t/macella 

 belongs to that section of the genus in which the anterior wings are 

 unicolorous. and the pale ashy-grey colour of the anterior wings 

 sufficiently distinguishes it from the more bronzy N. ruficajiitellfi . X. 

 atricajritella, X. anomalella, and the olive-coloured N. vitcerMa. From 

 A", jndverosi'lla, to which it bears considerable resemblance, it is dis- 

 tinguished by the less coarsely scaled appearance of the anterior wings 

 (Stainton). 



EGG-LAYING. The egg is laid on the upper surface of a hawthorn 

 leaf, either against the midrib or on the frill that edges the leaf-stalk, 

 but, in either case, invariably on the upper surface (Wood). Stainton 

 says on the " underside," close to the' midrib, or one of the lateral ribs. 



MINE. The larva makes a small blotch in leaves of hawthorn. 

 When the egg is laid against the midrib (and this is its most usual 

 position) the young larva commences its mine parallel with, and close 

 to, a rib, till it meets a transverse rib. the course of which it follows 

 for a short distance, and then returns on its path, making a closely 

 contorted mine, forming in the whole a blotch. The excrement of the 

 first portion of the mine is yellowish-brown ; it does not form a very 

 slender line, nor is it placed in little arcs of circles, but it forms a 

 moderately broad line. When the larva becomes more nearly full- 

 grown, the excrement becomes darker, and ultimately blackish-brown. 

 The larva comes out of the leaf to pupate (Stainton) . When the egg is 

 laid on the frill of the leaf-stalk, the newly-hatched larva mines until 

 it reaches the blade of the leaf ; the mine then runs along the edge of 

 it, as does the mine of X. yratimella, the mines of the two insects 

 being then so similar that they can be differentiated only by the 

 position of the egg (Wood). 



COMPARISON OF THE MINE OF N. PYGM.EELLA AND N. IGNOBFLELLA. 

 In the mine of X. pi/ffinaeclla, which is generally close to the mid-rib, 

 the excrement never forms a very slender line, and is at first yellowish- 

 brown ; in the mine of X. itjnobildla, which is frequently placed near 

 the edge of the leaf, the excrement at first forms a very slender line 

 (which is afterwards frequently included within the blotch-like mine), 

 and the excrement is always black (Stainton). 



LARVA. Length 2 lines. Pale amber yellow, the dorsal vessel a 

 little darker, and anteriorly rather greenish; the head is pale brown, 

 the mouth and two lines receding from it darker (Stainton). It mines 

 with the dorsum uppermost. 



COCOON. The cocoon is somewhat of the shape of a mussel-shell, 

 of a dull pink colour. The anterior segments of the pupa are pushed 

 out of the broader end of the cocoon before the emergence of the 

 imago. 



FOOD-PLANT. Crataeyw o.rijacanthn. Stainton gives " apple " also, 

 evidently an error. 



TIME OF APPEARANCE. The insect is double-brooded, the imagines 

 (which fly along hawthorn hedges in the early morning) appearing in 

 May and August, from larvte feeding in October and July respectively. 

 Stainton gives August 16th, 1851, imagines flying along hawthorn 

 hedges at G a.m. Bower found lamo abundantly at Mottingham, on 

 October 4th, 1892. Stainton bred imagines of the first brood on 

 January llth, 1853 ; April 8th and May 13th, 1853 ; May 25th, 1H53 ; 

 March 24th, April 1st and 8th, 1854 ; March 30th, 1855 ; March 25th- 



