26 SPOLIA ZEYLANICA. 



Fourth (ultimate) Instar. — A fully fed larva on the point of pupa- 

 tion is just over 7 mm. long, moderately stout, stoutest about middle 

 of body, tapering rather more rapidly towards the head. Colour 

 pale green, a dark rather reddish narrow medio-dorsal stripe ; latero- 

 dorsal tubercles red and surrounded with dark red dashes, which 

 assume rather a longitudinal direction, so that the larva seems to 

 have an interrupted rather broad latero-dorsal stripe. Head pale 

 green with dark ocellar marks on either side. Jaws and mouth parts 

 reddish. Long palps on either side of jaws # (fig. 4). 



The larvae, however, vary much, but seem divisible into three 

 types : — 



(1) Pale green with a distinctly reddish tinge ; a narrow darker 

 green dorsal stripe bordered on either side by a pale yellowish longi- 

 tudinal line ; head pale green with dark reddish ocellar patches ; 

 tubercles reddish-brown ; hairs white, as long as diameter of seg- 

 mental interstices, slightly and regularly dilated towards apex ; 

 prolegs pale green, almost transparent. 



(2) Paler green, on which the tubercles show up conspicuously 

 as a bright dark red. 



(3) Very much suffused with red, so as to appear of almost as 

 red a colour as the Drosera itself. 



The intensity of the dorsal stripe is very variable ; in some 

 specimens it is very distinct, in others quite obsolete. 



In its final instar the larva shows a decided preference for the 

 buds and seeds of the Drosera, eating a hole in the side of the seed 

 capsule and devouring the contents, but it also eats the leaves 

 (%• 6). 



General Remarks on the Larval State. — In all its stages the 

 larva is extremely similar to the Drosera and difficult to distinguish. 

 Even a full-grown larva may easily be passed over as a glandular leaf 

 seen edgewise, and vice versa. 



Ordinarily the larva seems sluggish, but can move along fairly fast 

 when it likes. It has, indeed, little incentive to move from the food 

 plant. When resting across the centre of the plant, with plenty of 

 food within reach, it seems to remain there for days, until a large 

 pile of flaccid dark-yellowish-green frass accumulates. 



In some cases the frass is jerked away by a rapid movement of 

 the anal extremity. In one instance which I noted it went about an 

 inch up into the air and fell on to the Drosera plant about half an inch 

 away from the larva ; but usually, I should imagine, it falls clear 

 of the food plant, or there would be no object in flicking it away in 

 this manner. However, as noted above, the frass often does accu- 

 mulate on the foodplant, so evidently this process of removal is not 

 an invariable habit, but is a peculiarity confined to certain indivi- 

 duals. 



