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| Elcysma ziroensis
Chada, Gogoi & Young, 2017
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Abstract
Elcysma, a small genus of zygaenid moths occurring in Nagaland, western China and Japan is recorded from Arunachal Pradesh, northeastern India for the first time. The other known species from northeastern India is E. dohertyi, so far known only from Nagaland by a single specimen collected by W. Doherty in 1889. A new species, E. ziroensis is hereby described. The other species of the genus is white in colour with prominent black veins whereas the new species has very broad black stripes along both sides of the veins taking over the white background on forewing and brown background on hindwing, making the moth look entirely blackish in colour. The new species also has the orange patch restricted to the upper base of forewing, whereas the other species of the genus has orange patch in whole of base of the forewing. The shape of the wing resembles that of E. dohertyi in being narrower forewing and hind wing. The wing venations is, however, markedly different from all other Elcysma species having five radius veins with three posterior radius sectors branching out to the apical area in forewing. The species also shows mimetic assemblage with B. lidderdalii which also flies together at the same locality.
Elcysma, a small genus of zygaenid moths occurring in Nagaland, western China and Japan is recorded from Arunachal Pradesh, northeastern India for the first time. The other known species from northeastern India is E. dohertyi, so far known only from Nagaland by a single specimen collected by W. Doherty in 1889. A new species, E. ziroensis is hereby described. The other species of the genus is white in colour with prominent black veins whereas the new species has very broad black stripes along both sides of the veins taking over the white background on forewing and brown background on hindwing, making the moth look entirely blackish in colour. The new species also has the orange patch restricted to the upper base of forewing, whereas the other species of the genus has orange patch in whole of base of the forewing. The shape of the wing resembles that of E. dohertyi in being narrower forewing and hind wing. The wing venations is, however, markedly different from all other Elcysma species having five radius veins with three posterior radius sectors branching out to the apical area in forewing. The species also shows mimetic assemblage with B. lidderdalii which also flies together at the same locality.
Keywords: Arunachal Pradesh, Elcysma ziroensis sp. nov., Lepidoptera, northeastern India, Ziro, Zygaenidae.
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| Image 5 A–F. Elcysma ziroensis sp. nov. A - Frontal view of head portion showing the labial palpus and dome-shaped chaetosemata (Eltringham’s organs) af dorsal; B - frontoclypeus, eye, labial palpus and dome-shaped chaetosemata af dorsal; C - posterior of fhe head portion; D - lateral view of the eye, chaetosemata and labial palpus; E - view of fhe bipecinate antennae; F - trenulum with two filaments arising from fhe hindwing. |
Elcysma ziroensis sp. nov.
Diagnosis: The species differs in colour pattern considerably from other species of the genus. The other species of the genus are bright and white in colour and black veins being very prominently seen. The new species has very broad black stripes running along both sides of the vein almost taking over the white background on forewing and brown background on hindwing. The shape of the wing resembles that of E. dohertyi and is unlike the other two species, which have broader forewings and hindwing. The wing venations, however, are markedly different from all other Elcysma species having five radial veins with three posterior radius sectors branching out to the apical area. The other three Elcysma species have four radial branches instead, as depicted (Fig. 1). The only radial vein in the hind wing, which is unbranched, extends to the costal area unlike the other three species, where it branches out to the termen and tornal area.
Etymology: The name of the species is derived from the type locality Ziro, Arunachal Pradesh in northeastern India.
Suggested common name: Apatani Glory is given as the English common name based on the tribal people living in Ziro.
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| Image 6A. Bhutanitis lidderdalii Atkinson, 1873 puddling on puddle 01-09-2010. Image 6B. Elcysma ziroensis sp. nov. puddling on rock 17-09-2010 (possfble male). Image 7A. Elcysma ziroensis sp. nov. female on hosf plant possfbly a species of Prunus, Rosaceae family 18-09-2016. Image 7B. Elcysma ziroensis sp. nov. female laying egg showing fhe papillae anales insering egg on crack of host plant 18-09-2016. |
Discussion and Conclusion
This is a brightly coloured diurnal species with a slow and fluttering flight. Its flight period matches with Bhutanitis lidderdalii Atkinson, 1873 with similar wing patterns, which are seen flying at the same time in the same locality. Both are fairly common in Talle Wildlife Sanctuary in Ziro. As zygaenid moths are chemically protected and aposematic (Naumann et al. 1999) and B. lidderdalii feeds on Aristolochiaceae rendering them unpalatable to predators, there appears to be a co-mimetic assemblage of the two species. A possible male individual was photographed (Image 6b) drinking at puddles on 17/IX/2010. This species does not appear to exhibit strong sexual dimorphism in wing pattern and size though the possible male appears to show a much darker ground colour and conspicuous markings than the female. The details of life history are unknown. Pictures of a female laying egg were taken on 18/IX/2016 and two photographs are depicted in Image 7a,b. From observations, this species has only been seen during autumn, notably in the month of September indicating that it is a univoltine species. This coincides with the laying of eggs in September. It is expected that the eggs will hatch in a few days and the larvae will hibernate in cracks in the trees where they are placed to survive during the cold winter at this high elevation of 1,700m in Ziro. The larvae will become active and feeding after diapause in the spring when new foliage appears. The final instar larvae will pupate in August and adults will appear again in September. This taxon appears to share a similar life history with E. westwoodii (Owada, 1992). The host plant appears to be a species of Prunus, Rosaceae family.
Punyo Chada, Monsoon Jyoti Gogoi and James John Young. 2017. A New Species of Zygaenid Moth Elcysma ziroensis (Lepidoptera: Zygaenidae: Chalcosiinae) from India. Journal of Threatened Taxa. 9(12); 11060–11066. DOI: 10.11609/jott.3419.9.12.11060-11066