A swallowtail butterfly disappearing from its previously known ranges from Myanmar and southern China to Vietnam has been recorded for the first time in India.
Three butterfly enthusiasts — Atanu Bose, Loren Sonowal and Monsoon Jyoti Gogoi — recorded the “extremely rare” Noble’s Helen (Papilio noblei) from three locations in the Namdapha National Park of Arunachal Pradesh between September 2019 and September 2021.
Their report was published in the latest edition of the Journal of Entomology and Zoology Studies.
The Noble’s Helen, closest to the Papilio antonio from the Philippines and characterised by a much large dorsal white spot, was once common in the montane forest at moderate elevations in northern Thailand.
Apart from Thailand, this species of swallowtail butterfly has been reported from Myanmar, Yunnan and Hubai regions of China, Laos, Cambodia and Vietnam.
“The species has not completely disappeared from Thailand but is now known to be very rare in the ranges it was previously recorded. The recording of Noble’s Helen for the first time in India is encouraging for nature lovers,” Mr. Bose told The Hindu.
Butterflies are considered vital indicators representing the state of biodiversity and key ecosystem functions.
The trio of Mr. Bose, Mr. Sonowal and Mr. Gogoi photographed the Noble’s Helen live from 19th Mile, Lunkai Nala, and near Deban Camp within the 1,985 sq. km-Namdapha, also India’s easternmost tiger reserve.
The locations are approximately 80 km aerially from Putao of Myanmar’s Kachin State, where this species of swallowtail butterfly was last recorded in April 1999.
Mr. Sonowal said the Noble’s Helen with a wingspan of 100-120 mm was initially thought to be an aberration of the Papilio helenus although the former has an extra white spot in the dorsum of the forewing. A closer study showed the Papilio noblei sports a consistent white spot and has a complete row of red lunules on the underside of the hind wing and discal white areas on the upper side of the hind wing.