410 BRITISH LEF1DOPTERA. 



larva throws out black frass from its mine. It feeds a little aftef the 

 fourth moult, before hibernation, which it commences early in October, 

 leaving its large blister-like mine, spinning a silken mat, and passing 

 a few silken threads over its back to support it on the underside of a 

 leaf. The larva commences to feed again early in February, and it 

 continues to do so throughout March and April, mining into the 

 leaves. It moults again at the commencement of May, and again 

 towards the end of May, making large blotches in the Centaurea 

 leaves, sometimes abstracting nearly the whole of the parenchyma of 

 the leaf. When full-fed (about the end of May or beginning of 

 June), the larva is said to remain for three or four days on the 

 surface of the ground, which it then enters for pupation. Buckler 

 notes full-fed larvs from May 30th-June 2nd, 1883. 



LARVA. When the newly -hatched larva leaves the egg it is short and 

 stumpy, with a small, black, shiny, retractile head, the prothorax with a 

 glossy brownish corneous plate, having a broad, black, dotted streak, 

 tapering to a point at the front and a black streak on each side. The 

 remaining segments are greenish-drab, and covered with a short, 

 white pubescence. After the first moult it is of a light green colour, 

 and the tubercles bear stiff bristles (Buckler calls the larva " a mass 

 of bristly tubercles "), but it becomes somewhat buff-coloured before 

 moulting. After the second moult it is still greener, becoming deep 

 flesh-colour before moulting again. After the third moult it is 

 dark slaty-green, the colour matching well with that of the leaves of 

 the food-plant, whilst a thin, dingy, purplish-brown, longitudinal, 

 dorsal line, spreading a little at each segmental division, runs between 

 the rows of dorsal tubercles. The tubercles are covered with short 

 radiating bristles of a drab colour, but before it moults again it 

 becomes much lighter, and is of an ochreous-green hue. After its 

 fourth moult, when fixed for hybernation, Buckler compares the 

 shape of the larva with that of a small hemp-seed, and says that there 

 are three rows of bristly, oval tubercles on either side of the body, 

 running in a longitudinal direction, so that six tubercles surround 

 each segment, except on the venter, which is naked, whilst between 

 the two which occupy the back of each segment is a black arrow-head 

 mark. The dorsal tubercles are dark, dingy, brownish-green, with 

 yellowish-green outer edges, relieved by a fine blackish line beneath. 

 After hybernation, the larva appears almost black, but, after feeding, 

 it becomes greener. After the next moult the tubercles become 

 bluish-green, the dorsal ones being strikingly defined by a creamy- 

 white sub-dorsal stripe, below which is a wider stripe of dark green. 

 After the last moult, when the larva is fitll-yroivn, it is described 

 by Buckler as measuring, when stretched out, from 13-14 mm. in 

 length, the greatest width, across the middle of the body, 5 mm. It 

 tapers a little at either end, and is rounded off behind, and also in 

 front, when at rest, with the first two segments retracted. The head 

 is extremely small and flattened, the segments are plump and very 

 deeply divided, the prothorax is smooth and glossy, the tubercles are 

 slightly raised, large, occupying nearly the length of a segment, 

 except the lowest (placed just above the feet), which are rather 

 smaller ; in shape, they are roundish ovate, the dorsal pair, side by 

 side on each segment, are set close and obliquely together in front, 

 leaving between them a small arrow-head-like space behind at the 



