Aberration or Valid Species?
Indeed, with the many lookalikes, particularly in the Lycaenidae and Hesperiidae families of butterflies, and also proven with the discoveries and re-discoveries of many species that were thought to have gone extinct in Singapore, many ButterflyCircle members are always keeping a sharp lookout for unusual behaviour or butterflies that look slightly different from the norm.
In this blog article, I discuss my personal observations of the wide variations in the size and arrangement of the ocelli on the hindwing of the Satyrinae, the Common Four Ring (Ypthima huebneri). These observations are purely from my records of field photographs of this species that may begin to suggest the possibility of a distinct species (or perhaps a subspecies) of the Common Four Ring that could exist in Malaysia and Singapore.
The Common Four Ring, like its larger cousin, the Common Three Ring (often referred to as a "Cinderella of Butterflies"), is as under-appreciated and more often than not, ignored by most butterfly watchers. Drab-coloured, unattractive and small, this species tends to keep close to the edges of forested areas where it discreetly goes about feeding on wildflowers or fluttering unassumingly amongst the grass.
The Common Four Ring is described as having greyish brown uppersides with a large subapical ocelli (eye spot) on the forewing above. The undersurface of both wings is greyish or pale buff brown with fine dark brown striations. The hindwing features four ocelli (if the two small tornal spots enclosed in a single yellow ring is counted as a single ocellus).
A Common Four Ring with the tornal ocellus and those in spaces 2 & 3 separated
With a number of years of observing this species in the field, and photographing them, I noticed that the arrangement and size of the ocelli on the hindwings fall into three main categories :
- Where the ocelli in spaces 2 & 3 are large and contiguous, and usually also contiguous with the tornal ocelli.
- Where the ocelli in spaces 2 & 3 are almost touching or contiguous but are separated from the tornal ocellus This seems to be by far the most typical of the majority of individuals of the species that I've encountered.
- Where all the ocelli are separated.
A typical example of a Common Four Ring where all the ocelli - tornal ocelli and those spaces 2 & 3 are contiguous
A Common Four Ring where the tornal ocellus and those in spaces 2 & 3 are distinctly apart from each other. Also note the striations on the hindwing are more sparse than those of the other individuals shown here, giving the hindwing a much "paler" appearance.
An example of a Common Four Ring where the ocelli in spaces 2 & 3 are contiguous, but separated from the tornal ocellus.
Food for thought, and more research needed before those questions can be answered with a higher level of confidence. Observers should continue to scrutinise individuals of the Common Four Ring when out in the field, and record their observations for future reference.
Text & Photos by Khew SK
Further References :