26 E. P. Siehhing-^Life-Hist., ^c, of moth Duomitus leuconotus. [No. 2, 



pupge have yefc been discovered and described. While, however, this is 

 the rule in the family, there are two notable exceptions, in each of these 

 cases the insects being of economic importance* Duomitus niger, an 

 insect closely allied to the species we are considering in this paper, 

 is the moth whose larva is known as the ' Black Borer * of Coffee- 

 planters, and has proved a source of considerable loss on Coffee estates, 

 whilst Zeuzera coffese, the moth whose larva is known as the Rod-Borer 

 (called by Hampson White-Borer^), commits great destruction in 

 Southern India and is a pest well-known to Coffee-planters. The 

 life-histories and habits of these two insects are more or less well 

 known. Of the other representatives of the family in the Indian 

 Region we have, however, little on record save the descriptions of the 

 moth, in some cases both the c? and $ of a species having been des- 

 cribed, in others the description of the ^ or the 9 ov\j being extant. 

 During the last few months I have had an opportunity here in Calcutta 

 of working out a portion of the life-history of one of the other known 

 species of Duomitus, that bearing the name of D. leuconotus, Walker, 

 and icnj observations are recorded below. 



The moth of which descriptions of both male and female are given 

 by Hampson in the Fauna is a large, stout, striking-looking insect with 

 a white thorax and greyish mottled wings. Hampson gives the wing 

 expanse in the c? as varying from 98-128 millim, that of the 9 being 

 given as 180 millims. The specimens obtained by me this year show 

 that there is a very much greater variation in size in both sexes. The 

 following dimensions of 32 moths all taken from the same tree are, I 

 think, well worthy of being placed upon record : — 



Expanse of wings 

 in (S 

 80 millims 

 110 

 108 

 90 

 83 

 78 

 90 

 95 

 82 

 73 



1 The real ' White Borer ' is the larva of a Cerambyx beetle. Vide my ' Note on 

 the Sandal wood boring insects of Madras ' published in the Appendix Series of tlia 

 Indian Forester, Vol. XXIX, No. 7 (1903). 



Exp 



anse 



of 



wings 





in 



$ 





,,, 



116 



m 



llims. 







88 





n 







88 





?) 







77 





5» 



.. 





JOO 





iy 







100 





n 



». 





J15 





5> 



... 





98 

 84 

 96 





>> 



5) 



