♂, Chiang Mai, Thailand.		♀, Chiang Mai, Thailand.
♂, Phetchaburi, Thailand.		♂ (ab), Chiang Mai, Thailand.

ON : Nacaduba coelestis Nicéville, 1887 OD : in Wood-Mason & Nicéville, J. asiat. Soc. Bengal, Part II. 55(4):366-367, pl.17, fig.11,♂. TL : Silcuri; Irangmara, [Cachar, NE.India]. Distribution : N.India to Myanmar, 'Andamans', Thailand, Laos, Cambodia, Vietnam, Yunnan. ● ssp.coelestis ● ssp.nanda

Type ♂, 'S.Andamans' [not stated]. (NZC) ; Sheela et al.,2019 : 148, figs.♂(Un),♂.

[ THAILAND ]
Prosotas aluta coelestis ; Pinratana,1981 : 64, pl.10, fig.20,♂(Un). (Chiang Mai; Chanthaburi; Chonburi; Kao Yai; Nakhon Nayok; Sakon Nakhon)
Prosotas aluta coelestis ; Ek-Amnuay,[2007] : 583, pl.264, figs.L140a♂,♂(Un). (Phitsanulok; Wiang Pa Pao)
Prosotas aluta coelestis ; Ek-Amnuay,2012 : 608, pl.275, figs.L165a♂,♂(Un). (Pitsanulok; Wiang Pa Pao)
Prosotas aluta coelestis ; Kimura et al.,2014 : 161, figs.♂,♂(Un),♂,♂(Un),♂,♂(Un). (Chiang Dao; Doi Suthep; Phu Khiewo; Nakohn Nayok; Kao Soi Dao; Kao Khiweo; Kuwai Yai)
Prosotas aluta coelestis ; S.Sophonviwatkul, C.Sunthornwiphat & T.Laola,2015- : Butterflies of Thailand, figs. (Kanchanaburi; Chanthaburi; Phetchaburi) (accessed: 2023.05.07)

[ LAOS ]
Prosotas aluta coelestis ; Motono & Negishi,1989 : 72, pl.103, figs.B3,♂,B4,♂(Un). (Luang Prabang; Vang Vieng)
Prosotas aluta coelestis ; Osada, Uémura & Uehara,1999 : 215, pl.111, figs.♂,♂(Un). (Vang Vieng)
Prosotas aluta coelestis ; Nakamura & Wakahara,2012 : 52, pl.15, figs.Ly-78,♀,♀(Un). (Phou Bia)
Prosotas aluta coelestis ; Suwa et al.,2013 : 26. (Nahin)
Prosotas aluta coelestis ; Onodera,2022 : 82, pl.212, figs.♂,♂(Un),♀,♀(Un). (Khammouan: Nahin; Xaisomboun: Nam Phang)

[ CAMBODIA ]
Prosotas aluta ssp. ; Kosterin,2020 : 322, figs.13-15,♂+♀(Un). (Siem Reap)
Prosotas aluta coelestis ; Chartier & Kosterin,2022 : 121. (Siem Reap)

[ VIETNAM ]
Nacaduba aluta coelestis ; Metaye,1957 : 90. (no loc.)
Prosotas aluta coelestis ; Miyazaki, Saito & Saito,2006d : 57, fig.L-58[59],♂. (Lam Dong: Madagui)
Prosotas aluta coelestis ; Monastyrskii & Devyatkin,2015 : 53. (C / S)

[ THAILAND ]
Mae Hong Son : 1♂.

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Chiang Mai : 11♂ 1♀ (incl. photo).

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Phetchaburi : 1♂.

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Phang Nga : 1♂ (photo by A.Giudici).

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[ LAOS ]
Bolikhamxai : 1♂.

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The butterfly is locally not rare in montane forests at low to moderate elevations (Alt. 350 - 700m). Males frequently come to the banks of streams and puddles to suck water.
The photo record of Pang Nga, P.Thailand appears to be this taxon, although there is no specimen. A comparison of the upper side of the specimen is needed.
The type locality of the original description is Silcuri; Irangmara, [Cachar, India]. However, Tite (1963:90) noted it as 'Andamans' and Sheela et al. (2019) showed the type specimen and gave the type locality as 'S. Andamans'. Here, I treat the type locality as "Silcuri; Irangmara" following the original description.

Wood-Mason, J. & Nicéville, L. de,1887 :
List of the lepidopterous insects collected in Cachar by Mr.J.Wood-Mason. Part II. Rhopalocera.
J. asiat. Soc. Bengal, Part II. 55(4):343-393, 4 pls.

Tite, G.E.,1963 : A Synonymic List of the Genus Nacaduba and Allied Genera (Lepidoptera: Lycaenidae).
Bull. Br. Mus. nat. Hist. (Ent.) 13(4):69-116, 91 tf, 2 pls. London.

♂, Chiang Mai, Thailand.	♂, Chiang Mai, Thailand.
♂, Chiang Mai, Thailand.	♂, Chiang Mai, Thailand.
♂, Phang Nga, Thailand. (photo by A.Giudici)

1999.07.11 - 2024.10.31.