New aspects of eye-head illusions in some British moths

Abstract

Photographs are shown of putative false eyes on wings of moths from Scotland. They can be grouped as simple ocelli (small dots and circles); as larger eye-like marks of various sizes, shapes, colours and positions, not recognisably based on any animal group; and as false eyedheads variously reminiscent of but not species-specific to snake, owl, raptor, primate, cat, rodent, fox and other canids. The most well-known, such as Emperor Moth Saturnia pavonia (Linnaeus, 1758) have large, ostentatious, multi-coloured false eyes but again no definitely recognisable model species. All this is consistent with the proposal of Janzen, Hallwachs & Burns (2010) that, in this large class of images, a pair of false eyes in a false face or head is the effective anti-predator component, rather than mimicry of species or groups that a predator might regard as harmful to itself. Examples are also shown and discussed of small blue false eyes, of eye-like marks on hindwings and on thorax rather than on forewings, of false eyes in forewing positions that can differ between individuals of a species, and of crypsis and aposematism that alternate repeatedly as needed within a single larval instar. A false-eyed head on the forewings of Alder Moth Acronicta alni (Linnaeus, 1767) adds to the well-known defensive images in the two final larval stages of that species. Finally, photographs are shown of putative false eyed-heads on forewings of three species of Microlepidoptera.