1903.] 167 



margins; prothoracic legs with a black chit.iiious spot above and an elongate 

 elliptical black chitinous spot between them bonoatli ; anal plale olive-grey, the 

 anterior edge blackish. Legs 16 (thoracic ^ ; abdominal^; anal {-). Lotiff. 6 mra., 

 in repose, stumpy ; extending to 9 mm. when in motion, then very thin and elongate. 



Ti/pe, Larva (91GG). Mus. W.slm. 



Hab. : Orange River Colony — Vredefort Road, Larva living 

 commensally in the nest of a social spider {Ster/odjjpliiis sp) and 

 feeding on insect remains, VII — 7. VIII, excl. (in England) 2G.VII 

 —7.x, 1902. 



Five s]}ecimens bred by Mr. R. I. Pocock, and three at Mertou 

 from nests eoilected by Captain Barrett-Hamilton. 



This species, for which I am indebted to Mr. Pocock, is very nearly 

 allied to Batrachedra ledereriella, Ti., from which it differs in its dark 

 head, but paler and less suffused wing-surface, the disc and dorsum 

 not being overspread with black dusting as in that species ; it also 

 differs in its much darker cilia and abdomen and in the form of the 

 annulations on the outer half of the antennae. 



I have bred ledereriella from a great variety of plants although 

 it appears always to be associated with the presence of spiders' webs 

 and accumulations of rubbish likely to contain them — empty seed- 

 pods, the nests of gregarious larvae, deserted webs of larvae on many 

 plants, even from seeds of Gistus and from galls formed by the larvae 

 of ColeopJiora stefanii, de Joannis, on Atri2)lea- halimus ; thus it would 

 appear that the habits of both species are practically identical, both 

 feeding on insect remains and debris in webs. 



Merton Hall, Thetford : 

 June, 1903. 



NOTES ON THE COMMENSALISM SUBSISTING BETWEEN 



A GREaARIOUS SPIDER, 8TEOODYPHUS SP., AND THE MOTH 



BATRACHEDRA STEGODYFROBIUS, Wlsm. 



BT R. I. POCOCK, F.Z.S. 



Early in the summer of last year, a nest of a species of the 

 South African gregarious Spider Stegodyphus was sent to me from 

 Vredefort Road in the Orange River Colony, by Capt. Gr. E. H. 

 Barrett-Hamilton, of the 5th Royal Irish Rifles. 



The nest, which travelled safely with its colony of spiders in a 

 small biscuit-tin, was transferred to a glass-case and mounted upon a 

 branch of poplar, stripped of its leaves. The spiders soon got to 



