470 sphingid^e. 



two short diverging arms ; upper surface rugose, underside 

 deeply concave ; a dorso -lateral spine near base. Colour of 

 head, thorax and wing-case very dark brown, rest of body 

 pale brown with numerous short longitudinal lines ; spiracles 

 black, cremaster brown, the shafts black. Length 50 mm. ; 

 breadth 10 mm. 



Habits. — Food-plants : Arissema Mart. ; Amorphophallus 

 Bl., family Aroidese. The larva when in the later instars 

 often rests on the stem of the plant, low down among the 

 surrounding herbage. The anterior segments are not so 

 strongly retractile as in others of the genus. The colour 

 becomes darker, with a greasy appearance, before pupation. 

 The pupa is very sluggish and rigid, the only perceptible 

 movement made when handled being a quivering which can be 

 detected by pressing gently on the bevels of the free abdominal 

 segments. The moths visit flowers after dark, but we have not 

 known them to come to light. There are probably several 

 broods in the season, as the moths emerge about three weeks 

 after pupation, except when the pupa is formed late in the 

 season. 



172. Rhagastis acuta (Walk.). (Fig. 120 B, genitalia). 



Zonilia acuta, Walker, 1856, p. 195 (Hindostan). 



Rhagastis acuta, Roths. & Jord., 1903, p. 794, pi. xiv, fig. 13 ($) ; 



Seitz, 1929, p. 568, t. 68 e. 

 Cheerocampa velata, Hampson (non Walk.), 1892, p. 91. 

 Theretra spec, Dudgeon, 1898, p. 414, n. 137, c, a. (Sikkim ; 



Bhutan ; up to 4,000 ft.). 



Imago. — <£$. In colour resembling R. aurifera, the subdorsal 

 tawny-ochreous stripe of the abdomen at least vestigial. 

 Underside of thorax and abdomen buff, less white than in 

 aurifera, the discal dot of fore wing smaller, the marginal 

 area not joined to the basal one ; marginal area of hind wing 

 narrower, not so much dilated before B, 3 . Two forms ; in 

 one the ochreous-buff band of the hind wing upperside is 

 reduced, being often just indicated near anal angle ; the 

 fore wing has scarcely a yellow tint, and the underside of both 

 wings is dull clayish-ochraceous with a tint of brick-red. 

 In the other form the fore wing upperside has here and there 

 an olive -yellow tone ; band of hind wing vestigial between 

 SC 2 and M 1 , underside of both wings brighter reddish and 

 ochreous. The marginal border of the underside of the fore 

 wing often appears above in both forms. Second segment 

 of palpus strongly narrowed towards base, triangular, entirely 

 different from the segment of velata, aurifera etc. ; cavity 

 of first segment large. External row of spines of first protarsal 

 segment doubled and trebled. Expanse : ^$ 66-72 mm. 



