OCR Text |
Show of the group in which it is manifest, the abundance and wide range of individuals in the species as well as of the species themselves, together with the remarkable predominance of mimetic resemblances among them-all tended to create a strong suspicion that the mimicry is Mullerian (synaposematic). This suspicion is now justified. The discovery of many Bornean Longicorn mimics of Clytince renders it in every way probable that the group is specially defended by some unpalatable quality, and sometimes develops warning colours of its own which are deceptively resembled by other beetles, although it usually makes use of warning colours which are common to more aggressive and even more highly-protected insects. Thus the conclusions which were found to hold in the case of the Cleridse (p. 248) also apply, with equal probability, to the Clytince. Since the above was written Mr. Gahan has shown me a beautiful example of Batesian or Mullerian mimicry within the group of Clytince, the common Demonax walkeri (Pasc.) being resembled in the closest manner by the rarer Perissus myops (Chev.). Both beetles had come to the British Museum in a single consignment from Ceylon. There is similarly a very remarkable resemblance, probably Mullerian, between Xylotrechus pedestris and Demonax viverra (compare figs. 29 & 35 on Plate X X .).-E. B. P.] COLEOPTERA OTHER THAN LONGICORNS AS M lM IC S . Mimic. Tillicera sp., near bibalteata (Gorh.) (Fam. Cleridse). Plate X X III. fig. 49. Model. Mutilla sp. near urania (Sm.). Plate X X III. fig. 48. The Mutilla has a red head and thorax and black abdomen, the second abdominal segment bears a white spot, the third segment is covered with a creamy white pubescence. In the beetle, the eyes and front of head are black, the vertex of the head and the prothorax are red; the elytra are black with one white band replacing the white spot and another sub-apical band paralleling the white abdominal segment of the Mutilla. Curiously enough, the male of this species of Mutilla bears a white band in place of a white spot, and hence the beetle more closely approaches the male than the female in its markings : still there is no question as to which sex serves as the model in this case. Several specimens of the same species of Tillicera and of a closely-allied one are in the Hope Collection, Oxford, all collected by Dr. A. R. Wallace in Sarawak. IV. LEPIDOPTERA AS MIMICS. So much has been written, by abler pens than mine, on mimicry amongst the Eastern Lepidoptera inter se, that I have confined myself to drawing xip merely a table of such mimetic species as occur in Borneo, with the addition of a few notes on the bionomics of certain species. Three remarkable examples of lepidopterous 252 MR, R. SHELFORD OX MIMETIC INSECTS AND [Nov. 4, |