IN DEFENSIVE COLORATION 369 



more remarkable one has been provided by the acute 

 observation of Portschinski. 1 The great Russian natural- 

 ist has suggested that the mature and semi-mature larva 

 oi Stauropus fagi (the Lobster Moth) resembles a cater- 

 pillar attacked by a Pentatomid bug. The bug itself is 

 represented by the flattened caudal shield, of which 

 the terminal processes resemble antennae. In its usual 

 position, this shield is bent forward over the back of the 

 larva, so that the flattened ventral surface becomes dor- 

 sal, the convex dorsal surface ventral, the antenna-like 

 processes anterior. It thus resembles very closely the 

 appearance of a bug seated on the back of the cater- 

 pillar and engaged in sucking its juices. 



The extraordinary mimetic resemblance of the Mem- 

 bracidae, in which the appearance is wrought in the 

 visible shield, and not in the insect which it conceals, 

 has been described and figured on pp. 258-9. Other 

 remarkable instances to be found in the same Essay need 

 not be further mentioned. 



8. Mimetic Resemblance to Cryptic Models. — A set of 

 examples, very rare in Mimicry, is to be found in the 

 numerous Longicorn beetles which resemble Rhyncho- 

 phora. Mr. Shelford 2 has shown that in Borneo all three 

 groups of Rhynchophorous beetles, the Curculionidae 

 (weevils), the Anthribidae and the Brenthidae are thus 

 mimicked; in South Africa, Mr. Marshall 3 has shown 

 that the first-named group provides models for Longi- 

 corns. Wallace 4 suggested long ago that the weevils and 

 Anthribidae are protected by their excessive hardness, 

 and are on this account mimicked by less well-protected 

 Longicorns. Although in some cases the Rhyncho- 

 phorous models possess a conspicuous warning pattern, 

 the great majority appear to bear a Procryptic colouring. 

 This appearance is, however, often deceptive, inasmuch 

 as the habits of the insect may render it conspicuous. 



1 Coloration Marquante et Taches ocelle'es, V., St. P&ersbourg, 1897, 

 p. 51, fig. 25. 



2 Proc. Zool. Soc, Lond., 1902, vol. ii, pp. 245-7. 



3 Trans. Ent. Soc, Lond., 1902, p. 523. Consult also the whole section 

 on pp. 522-5. 



* On Natural Selection, London, 1875, p. 94. 



POUITON B b 



