A sighting of Plastingia naga (de Nicéville, [1884]) (Lepidoptera: Hesperiidae: Hesperiinae) from central Assam, India

Plastingia naga (de Nicéville, [1884]) (Hesperiidae) is a widely distributed butterfly that occurs from Assam (northeastern India) east to Myanmar, Malaysia, Thailand, Laos, Indonesia, Borneo and Philippines (Evans 1932; 1949 & http://yutaka.it-n.jp/hes/92120001.html). This species is “rare” in northeastern India (Evans 1932) but it is moderately common in the Malayan region. As per Butterflies of Singapore, it is a moderately common butterfly in Singapore which has been frequently sighted near the larval host plant Fishtail Palm Caryota mitis.

Plastingia naga was first described by de Nicéville (1884) as Hesperia naga from Sibsaghar (upper Assam), when one female specimen of this species was collected, which is preserved in the Indian Museum, Calcutta. Later, it was also collected by Moore & Swinhoe from the Khasi and Jaintia Hills, Meghalaya (Swinhoe 1912–1913).

On 10 Oct 2014, at around 10:00hr, a solitary individual of Plastingia naga was sighted in Panbari Reserve Forest, central Assam (Fig. 1). The individual was sitting on a leaf in the shadows at a height of about 1.5m from the ground. The habitat predominantly comprised evergreen trees and shrubs. The authors photographed the species (Image 1 a,b) after which it took wing and did not return. Regular visits to the same site yielded no further sightings of Plastingia naga.

Plastingia naga has a blackish-brown ground colour with distinct pale white spots on the underside. Its upper side is marked with obscure yellow spots, and a small spot in cell may be present. The female is morphologically similar to the male. The wing span of the species is 33–38 mm (Evans 1932).

Panbari Reserve Forest lies between Kaziranga National Park and the foothills of West Karbi Hills in central Assam. The reserve is bounded by National Highway 37 on the north, a human settlement on the east, and a tea garden and Karbi foot hills on the south-west. The altitude of the area varies from 80–360 m. The butterflies of this area were well studied by Gogoi (2013, 2015).

In 2013, Gogoi reported 137 species of the Hesperiidae butterfly from Panbari Reserve Forest and recorded three species of Lancers; Salanoemia fuscicornis, Pyroneura margherita margherita, Pyroneura niasana burmana but did not report any Plastingia naga (Gogoi 2013).

There are only a few recent records of Plastingia naga from mainland India. In recent times it has been sighted from the Siju Wildlife Sanctuary, South Garo Hills, on 22 May 2015 (Karmakar 2016). Karmakar reared Plastingia naga from its larval stage. This species has also been sighted from the Barail Range in September 2015 (Monsoon Jyoti Gogoi pers. comm. 2015). This record from Panbari shows the importance of these habitats for rare species in the last remaining forest patches of central Assam and the need to conserve these habitats. Further, long term monitoring is necessary to reveal the ecology and distribution of such butterfly species in northeastern India.

References

Anonymous (2014). Plastingia naga de Nicèville, 1884. Butterflies of Singapore. http://butterflycircle.blogspot.in/2013/07/lifehistoryofchequeredlancer.html. (Accessed on October 2014).

de Nicéville (1884). On new and little known Rhopalocera from the Indian Region. Journal of Asiatic Society, Bengal 52 Pt.II (2/4): 65–91, pl. 1, 9–10.

Evans, W.H. (1932). The Identification of Indian Butterflies - 2nd Edition. Bombay Natural History Society, Mumbai, India, 464pp+32pls.

Evans, W.H. (1949). A Catalogue of the Hesperiidae of Europe, Asia and Australia in the British Museum (Natural History). Trustees of the British Museum, London, 502pp.

Gogoi, M.J. (2013). Notes on some skipper butterflies (Lepidoptera: Hesperiidae) from Panbari Forest and its adjoining areas, Kaziranga-Karbi Anglong, upper Assam, India. Journal of Threatened Taxa 5(13): 4759–4768; http://dx.doi.org/10.11609/JoTT.o3340.4759-68

Gogoi, M.J. (2015). Observations on lycaenid butterflies from Panbari Reserve Forest and adjoining areas, Kaziranga, Assam, northeastern India. Journal of Threatened Taxa 7(15): 8259–8271; http://dx.doi.org/10.11609/jott.2467.7.15.8259-8171

Karmakar, T. (2016). Plastingia naga de Nicéville, 1883 - Silver-spotted Lancer. In: Kunte, K., P. Roy, S. Kalesh & U. Kodandaramaiah (eds.). Butterflies of India, v. 2.23. Indian Foundation for Butterflies. http://www.ifoundbutterflies.org/sp/2950/Plastingia-naga.

Swinhoe, C. (1912–1913). Lepidoptera Indica. Part X. Rhopalocera- Hesperiidae. Lovell, Reeve & Co. Ltd., London, 364pp+757–835pls.