66 Indian Museum Notes. [Vol. V. 



The various stages of its metamorphosis may be described as 

 follows : — 



EGG. — The eggs are laid by the moth near the axils of the leaves 

 of the plant. They are flat, circular, one-twenty-fifth of an inch in 

 diameter, and are white when first deposited, turning yellow as they 

 approach the hatching point. The period passed in the egg stage 

 is not at pnesent known. 



LARVA. — The young larva hatches out and penetrates the stalk at 

 or near the joint and commences to tunnel through the soft pith. 

 The growth of the borer worm is very rapid, but the approximate 

 number of days parsed in this stage has not been observed. The 

 borers are quite active and occasionally leave their burrows and 

 crawl about on the outside of the stalk seeking another place to 

 enter. When full grown the larva is about an inch long-, rather 

 slender,nearly cylindrical and creamy-white in general colour, and often 

 speckled with black spots ; head yellow, mouth parts black. Upon 

 attaining its full size the larva bores to the outside of the cane and 

 makes a large round hole for its future exit — a hole which is usually 

 one-fifth of an inch in diameter. It then retires to its burrow and 

 transforms into a pupa. The insect hybernates {e.g., passes the 

 winter) almost exclusively in the larval stage, and the grubs are often 

 to be found very abundant in the seed cane, discarded tops left in the 

 fields, and, to some extent, in the stubble. 



Pupa. — The pupal stage is passed in the burrow within the cane 

 stalk. The pupa is slender, brown, three-quarters of an inch in 

 length. This stage lasts but a few days. 



IMAGO. — The moth is light greyish-brown in colour with a spread 

 of wings of about an inch and a quarter. In the female the hind- 

 wings are nearly the same colour as the forewings, but in the male 

 the former are silvery white. Sir G, F. Hampson in his identification 

 of the insect described the species as follows : — 



"Male: yellowish-brown suffused with fuscous ; forewing with the costal area 

 rather darkish ; traces of dark specks below middle of cell and at lower angle; 

 the veins of outer area slightly streaked with fuscous : a marginal series of black 

 specks. Hind wing whitish with slight fuscous tinge." 



" Female : paler, ihe hind wing white." 



"The form partellus has on the forewing of male a highly curved antemedial 

 series of short fuscous streaks, a slight yellowish patch in end of cell, and oblique 

 series of diffused fuscous streaks from apex to middle of inner margin, and a sub- 

 marginal series of specks; female with some diffused fuscous from apex round 

 lower angle of cell, or sometimes nearly evenly suffused with fuscous, with a dark 

 fuscous patch beyond cell." 



