1903.] Papers. 119 



4. On the life history of a species of Arbela, new to the Indian 

 Museum Collections, which is proving a destructive pest in Casuarina plan* 

 tations in Madras. — By E. P. Stebbing. 



(Abstract.) 



How little is really known about our insect foes in India is becom- 

 ing increasingly evident day by day. An insect suddenly swarms over 

 an area in numbers owing to some particularly favourable conditions in 

 its surroundings, it commits serious depredations in the fields, orchards, 

 or forests of the tract it is invading and specimens are sent for identifi- 

 cation to specialists. The odds are greatly in favour of its being un- 

 known to science. Instances of this state of affairs are numerous, and it 

 may be said that, leaving out of account the butterflies and one or two 

 other groups which have received attention, it is easier to pick up a new 

 species than to collect one that is known. The moth known as Arbela 

 tetraonis Moore, about whose life-history I wish to put on record a few 

 notes, furnishes an illustration of the aptness of the above remarks, 

 since although new to the Indian Museum Collections and rare in 

 collections generally, its larva has been known for some years as a 

 destructive bark eater in Casuarina (Casuarina equisetifolia) plantations 

 on the eastern seaboard of Madras. There may, however, be said to be 

 some excuse for its having remained so long undescribed, since it 

 belongs to a family of moths closely allied to the Cossidse which have 

 been little studied and the life-histories of whose members are little 

 known, the larvae often living in the interior of the woody portions of 

 trees. The moths are rarely seen ; in colouration they often greatly 

 resemble the surfaces upon which they rest, and being poor fliers they 

 do not move about much and, owing to the method of living of the 

 larvae, they are difficult to breed out. The pupal stage of the English 

 Goat Moth is known and has been described, but very little is known 

 about the pupae of other members of the Cossid family, and practically 

 nothing is on record about the Indian Arbelidse. The description of the 

 pupal stage of this insect given in the paper is therefore of some in- 

 terest and importance. 



After noting on the members of the families represented in the 

 Indian Museum, including an unnamed specimen, which is labelled ' de 

 Niceville, Calcutta, 1891,' and which is not unlike the insect here dealt 

 with, the paper gives a description of the larva, pupa, and moth* • and 

 then alludes to the portions of the life-history at present known and 

 describes the method of feeding of the larva. This is important. The 



# This insect has since been very kindly identified for me by Mr. G. C. Dudgeon 

 as Arbela tetraonis Moore. E.P.S., 2nd November, 1903. 



