

NEPTICULA AURELLA. 231 



the cocoon is moderately smooth, and only very faintly reticulated with 

 fine lines of a tint just darker than the cocoon itself. [Described 

 July 5th, 1898, under a two-thirds lens from cocoons sent by Mr. W. 

 H. B. Fletcher.] When the larva is full-fed, it gnaws a hole, exactly 

 of the same shape and form as the front and sides of the head of the 

 larva, and gradually draws its body from the mine. It then seeks a 

 suitable place in which to make its cocoon ; this is sometimes spun on 

 a leaf or twig, sometimes on a dead leaf on the ground, and larvae 

 have been known to penetrate the sand in a breeding-cage to the depth 

 of an inch or more, and there spin their cocoons. When it has selected 

 a suitable position, it commences carpeting with silk the part of the 

 leaf or twig on which it is resting, and thus forms the floor of its 

 cocoon. This being done, the larva, keeping its body in an apparently 

 cramped position, gradually throws a number of silken filaments over 

 its body, fastening them to the sides of the floor of the cocoon, thus 

 giving a convex form to the structure. This forms the framework 

 of the cocoon, but by continuous spinning it is entirely completed in 

 about nine hours (Healy) . The cocoon is of an irregular shape, rather 

 flat, with scalloped edges, and varies in colour from pale dirty-green 

 to pale brown. The pupal state lasts about three weeks (Stainton). 

 The cocoon is whitish-green, with a flat angulated margin (Hind). 



QUIESCENT PERIOD PRECEDING PUPATION. The body of the larva is 

 curled round in the newly-formed cocoon, and occupies nearly the 

 whole of its interior. A fortnight later its body is much shrunk, so 

 that it lies in the centre of the cocoon with much room to spare. At 

 this time, the larva is only 2'" long and 1'" wide at its stoutest part, 

 having lost just half its length by the peculiar shrinking process it 

 undergoes ; its body is also of a paler yellow than when it constructs 

 its cocoon. The larva is now quite motionless, but, a day or two 

 afterwards, the head becomes slightly swollen, and gradually the four 

 anterior segments assume the same swollen appearance ; the posterior 

 segments also become slightly swollen, but not nearly so much so as 

 the four anterior segments. The anterior segments continue to swell 

 until they commence to crack, and the skin slowly contracting, the 

 pupal state is assumed. The larval skin is ultimately collected in a 

 little heap at the posterior end of the pupa (Healy). 



PUPA. The newly formed pupa presents a very pretty appearance, 

 the head, thorax and wing-cases being enclosed, as it were, in a covering 

 resembling very thin white glass, the abdomen being of a pale sulphur- 

 yellow ; the pupa is then exceedingly tender, and can only be touched 

 with the greatest caution. About three-parts down the dorsal surface 

 of the abdomen a pale brown patch is observable, and on the back of 

 the head are two parallel chains of dusky -coloured dots ; after two 

 days the eyes become pale brown, and the two parallel chains of dusky 

 spots disappear, their place being occupied by a pale reddish patch, 

 and three little dark spots visible near the base of the thorax. The 

 colour of the abdomen gradually deepens to orange-yellow ; the next 

 day the spots near the base of the thorax disappear, and also the 

 brown patch on the abdomen. The pupa, which has hitherto remained 

 inactive, now wriggles its abdomen about, and its surface becomes 

 much firmer. About a week later, the brown abdominal patch 

 reappears and shows through the ventral surface, whilst two short 

 projections, which proved to be the ends of the wing-cases, and which 



