60 SPHINGIDiE. 



ring ; seven sharply defined yellow oblique stripes on 5 to 11, 

 each stripe extending upwards artd backwards to near the 

 dorsal line of the segment behind, that on 11 extending 

 backwards to the base of the horn ; each stripe edged above 

 with dark blue, sharply defined at the common edge but 

 diffuse dorsad. Horn canary-yellow ; true legs black ; 

 prolegs and claspers green ; anal flap green edged with yellow. 

 Spiracles oval, yellowish-white with the central slit black, 

 the whole bordered with brownish -green. 



Yellow form : The green colour of head and body replaced 

 by canary-yellow, the markings remaining the same. 



Brown form : Head ochreous with the stripe dark brown ; 

 body brown ; on segments 2 to 4 a broad black dorsal stripe 

 and below it a broad ochreous stripe ; the subspiracular area 

 dotted and streaked with brown ; a brown oval marking 

 on each side of the dorsum of 2 ; oblique stripes purple ; 

 horn ochreous, legs and prolegs black, claspers brown. Length 

 90 mm. or more ; breadth 12 mm. ; horn 10 mm. 



Pupa. — Very similar to that of lachesis in shape, surface 

 marking and colour. Segment 2 shorter in proportion than 

 in lachesis, and the surface of the pear-shaped sculpturing on 

 4 flat, not concave as in lachesis. Antenna slightly longer than 

 fore leg. Cremaster stout, triangular, dorsal surface rugose, 

 tip ending in two teeth, each bearing a bristle. Length 57 mm. ; 

 breadth 14 mm. 



Habits.— The food-plants belong to much the same families 

 as those of lachesis, but styx styx feeds also on Sesamum 

 indicum DC, of the family Pedaliacese. The habits are very 

 similar to those of lachesis. The eggs of this species are 

 often attacked by a hymenopterous parasite, which lays its 

 eggs in or on those of the moth. Infected eggs become 

 gradually mottled black and white as the larvae of the parasite 

 develop. As many as twenty parasites may emerge from one 

 egg. The larvae sometimes occur in such numbers as to 

 •cause serious damage to crops, such as Sesamum indicum DC 



Genus HERSE Oken. (Fig. 10). 



Oken, 1815, p. 762 ; Roths. & Jord., 1903, p. 6 ; id., 1907, p. 6 ; 

 Jordan, 1911, p. 233. 



Genotype : convolvuli Linn. 



Imago. — " $ $. Tongue very long, strongly attenuate apicad. 

 Palpus without cavity in the scaling at the end of the first 

 segment externally, second segment about a quarter shorter 

 than the first ; inner surface of first longitudinally impressed ; 

 cavity of second deep, covered by a conspicuous roof of scales. 

 Antenna almost equal in width from near base to near hook 

 in (J, slightly clubbed in $. Tarsi slender ; fore tarsus with 

 several prolonged external spines ; mid- and hind tarsus 



