Sighting of Elymnias panthera (Lepidoptera: Nymphalidae:Satyrinae) in West Bengal, eastern India
Arjan Basu Roy 1, Ujjal Ghosh 2 & Krushnamegh Kunte 3
1 Nature
Mates-Nature Club, 6/7 Bijoygarh, Jadavpur,
Kolkata West Bengal 700032, India
2 Divisional ForestOfficer (IFS), Wildlife III Division, P.O. Nilkuthi, District Coochbihar,
West Bengal 736101, India
3 FAS Center for
Systems Biology, Harvard University, 52 Oxford St, Northwest Lab Room 454.40-2,
Cambridge, MA 02138, USA.
Email: 1 naturemates@gmail.com, 3 KKunte@cgr.harvard.edu (correspondeing author)
Date
of publication (online): 26 January 2010
Date of
publication (print): 26 January 2010
ISSN 0974-7907
(online) | 0974-7893 (print)
Editor: Maan Barua
Manuscript
details:
Ms # o2280
Received 02
August 2009
Final received
14 September 2009
Finally accepted
08 December 2009
Citation: Roy, A.B., U. Ghosh & K. Kunte (2010).
Sighting of Elymnias panthera (Lepidoptera: Nymphalidae: Satyrinae)
in West Bengal, eastern India. Journal of Threatened Taxa2(1): 670-671.
Copyright: © Arjan Basu Roy, Ujjal Ghosh & Krushnamegh Kunte 2010. Creative
Commons Attribution 3.0 Unported License. JoTT allows unrestricted use of this article in any medium
for non-profit purposes, reproduction and distribution by providing adequate
credit to the authors and the source of publication.
Acknowledgments:We thank Lipika Roy (Divisional Forest
Officer, Nadia-Murshidabad Division, Dept. of
Forests, Govt. of West Bengal) for facilitating field
work.
Many Malayan
butterflies have peculiar distributional ranges regarding their penetrance in the Indian Region. Some species have colonized the nearby
Andaman and Nicobar Archipelago but they do not occur further north in mainland
northern Indo-China and northeastern India, while other species occur in these
northern mainland areas without having colonized the Andaman and Nicobar
Archipelago. One such interesting
example is Elymnias panthera Fabricius, 1787, the Tawny Palmfly. The species ranges from southern Thailand
southward throughout most of Southeast Asia and SundaIslands in several subspecific forms (Talbot 1947; d’Abrera 1985; Pinratana 1988). It is represented within Indian limits by E.
p. mimus Wood-Mason & de Nicéville,
1881, a subspecies endemic to the Nicobar Islands (Evans 1932; Talbot
1947). However, the species does not
occur north of Peninsular Thailand either in northern Indo-China or in
northeastern India. It is unknown what
restricts distributional range of E. pantherain Southeast Asia, or of its subspecies to smaller geographic areas within this
region.
With this
background, we report sighting of E. panthera from
the Bethuadahari Wildlife Sanctuary near the town of
Krishna Nagar (23023’N & 88030’E), Nadia District, West Bengal, eastern
India. This is a possible range
extension of the species by at least 2,000km. While watching butterflies in the sanctuary on 04 February 2008, at 0950
hr, one of us (ABR) spotted an Elymnias perched
at ~2m off the ground in a small tree. It flew away after just a single picture was taken (Image 1), so AB was
not able to capture the butterfly for closer examination. However, it was
striking that, when the butterfly flew, it was missing the distinctive bluish
fore-wing apical band and bright orange hind-wing margin of the male or the
mimetic orange and black pattern of the female E. hypermnestra(Linnaeus, 1763), that is common in this area. On closer inspection of the colour pattern and
markings that are evident in Image 1, KK identified the species as E. panthera based on a key character that distinguishes E.panthera from other Elymnias,
that its hind-wing underside is marked by six prominent ocelli(Evans 1932; Talbot 1947). In comparison
with undersides of other similar Elymnias species,
the large black-ringed white costal spot is also distinctive (d’Abrera 1985).
Two factors need
to be addressed while considering this sighting of E. panthera so far outside its known range. The
first factor is obviously the huge distance between its previously known range
and the new locality from which we are reporting this sighting. Butterfly fauna of the Sikkim-Bengal-Assam
region has been reasonably well documented, hence it
would seem remarkable if this species has gone unnoticed from this area for
~220 years since its original description. However, we note that Elymnias are
crepuscular and usually active in dense forests (Talbot 1947), and therefore
difficult to locate. Butterfly collectors may also have earlier missed E. panthera in this area due to its vague mimetic
resemblance on the upper side of the wings to the much commoner Euploea midamus Linnaeus,
1758 (Corbet et al. 1992). We suspect that the lack of records for E.panthera may perhaps be explained by these
behavioral peculiarities and its presumed rarity in these parts. A parallel
example that bolsters this suspicion is the recent record and range extension
of E. obnubila from southern Mizoram in
northeastern India (Kunte 2009).
The second
factor is that Elymnias usually occur
in evergreen and semi-evergreen forests, where several species of palms – their
larval host plants – mostly grow (Robinson et al. 2001). The forest in which E.panthera was sighted is a deciduous forest in
which the West Bengal Forest Department has maintained patches of timber trees
and plants of other economic importance since the 1960s. Thus, this was not a typical habitat for E.panthera. It is possible that this specimen had been inadvertently imported as an
egg or a caterpillar along with an exotic palm from SE Asia. However, as far as we or the local forest
department know, palms have not been recently imported in this area from the
native range of E. panthera. Hence, we report this sighting with a
tentative suggestion that this may be a range extension of this species. We are conducting regular butterfly surveys
in this and neighboring areas of northeastern India to confirm whether there is
a resident population of this species in northeastern India, and to delineate
distribution of the species in the region in case more specimens are sighted.
References
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