♂, Mae Hong Son, Thailand.		♀, Xieng Khouang, Laos. (photo by H.Onodera)
♂, Mae Hong Son, Thailand.		♀, Chiang Mai, Thailand.
♂, Lampang, Thailand.		♂, Chiang Mai, Thailand.
♂ genitalia, Mae Hong Son, Thailand.

ON : Halpe arcuata Evans, 1937 OD : Entomologist 70(1): 17-18. TL : "Karen Hills, Burma" [Karen Hills, Kayah State, Myanmar]. (NHML) Distribution : Nepal, Sikkim, Assam, Myanmar, Yunnan, Thailand, Laos, Vietnam, Guangxi.

Halpe muoi Huang, 1999 : Lambillionea 99(4): 664-665, figs.25(HT,♂), 34(HT,♂Un), 98-a(♂genitalia). TL. Qujing, N.E.Yunnan. (QEC)

muoi ; Holotype ♂, Jul.1992. Qujiang, 1500m, N.E.Yunnan. X.S.Muo leg. (Qingdao Education College, China)

[ THAILAND ]
Halpe arcuata ; Pinratana,1985 : 56, pl.19, figs.111,♂,♂,♂(Un). (Chiang Mai; Chaiyaphum; Nakhon Nayok)
'Halpe kusala ; Kimura,1997 ; 45-46, pl.3, figs.47,♂,48,♂(Un). (Mae Hong Son)'
Halpe arcuata ; Ek-Amnuay,[2007] : 778, pl.357, figs.H128,♂,♂(Un). (Chiang Mai)
Halpe arcuata ; Kimura et al.,2011 : 58, figs.♂,♂(Un). (Doi Pha Hom Pok; Chiang Dao; Doi Inthanon; Bang Salok; Nakohn Nayok; Mae Sohd; 'Kao Poh Ta')
Halpe arcuata ; Ek-Amnuay,2012 : 830, pl.383, figs.H125,♂,♂(Un). (Chiang Mai)
'Halpe arcuata ; Küppers & Janikorn,2017 : 87, fig.Abb.H-112. (Phang Nga)'
'Halpe arcuata ; S.Sophonviwatkul, C.Sunthornwiphat & T.Laola,2023- : Butterflies of Thailand, fig. (Phetchabun) (accessed: 2023.07.14)'

[ LAOS ]
Halpe arcuata ; Motono & Negishi,1989 : 81, pl.113, figs.A9,♀,A10,♀(Un) ; B5,♂B6,♂(Un). (Phatong)
Halpe arcuata ; Osada, Uémura & Uehara,1999 : 223, pl.138, fig.♂(Un). (Phong Saly)
Halpe arcuata ; Nakamura & Wakahara,2012 : 58.
Halpe arcuata ; Onodera,2022 : 112, pl.249, figs.♂,♂(Un),♀,♀(Un). (Xiengkhoung: Tha)

[ VIETNAM ]
Halpe arcuata ; Devyatkin & Monastyrskii,2002 : 148. (Ba Be)
Halpe arcuata ; Miyazaki, Saito & Saito,2007b : 10, figs.H-54,♂,♀. (Lam Dong: Dambri; Dong Nai: Thac Mai)
Halpe arcuata ; Monastyrskii & Devyatkin,2015 : 78. (N: Bac Can)

[ THAILAND ]
Mae Hong Son : 9♂. (5♂ genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Chiang Rai : 2♂.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Chiang Mai : 7♂ 1♀. (1♂ genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Lampang : 5♂ (incl. photo), (2♂ genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Phrae : 1♂.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Nan : 3♂. (2♂ genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Phetchabun : 2♂ (genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Tak : 1♂ (genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Chanthaburi : 1♂ (genitalia dissected).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

[ LAOS ]
Xieng Khouang : 1♂ 1♀ (photo by H.Onodera).

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

The butterfly is locally not rare in montane forests at low to moderate elevations (Alt. 200 - 1500m). Males are territorial on trees at hilltops and occasionally come to the banks of streams and puddles to suck water.
The white spots on the UpF are highly variable. The small white cell spot on the UpF is occasionally present, as mentioned by Evans (1949). This taxon can be distinguished from Halpe fushigina and Halpe scissa, which are very similar in pattern, by the presence or absence of pale brown patches on the androconial brand on the UpF, which are conspicuous in fushigina and scissa but absent in arcuata and lao. The population from W.Malaysia was previously treated as Halpe arcuata, but is now considered to be Halpe fushigina. Halpe lao is also very similar to this species. Sufficiently fresh specimens can be distinguished by the colouration of the cilia on the forewing. Halpe lao has a chequered pattern of dark brown and brown from vein 2 to the apex on the forewing whereas arcuata is uniformly brown. However, the cilia are easily lost, so examination of the male genitalia is necessary for accurate identification.

Kimura et al. (2011) recorded it from Kao Poh Tha, Surat Thani, which could be a variation of Halpe scissa or Halpe fushigina. Küppers & Janikorn (2017) recorded it from Phang Nga, and Sophonviwatkul et al. recorded it at Phetchabun, but these cannot be confirmed by photographs. Therefore, these records are not included here.
Further taxonomic and distributional studies are needed.

♂ androconial brand on the UpF.
arcuata	lao	fushigina	scissa scissa (Chiang Mai)	scissa scissa (Ranong)

Evans, W.H.,1937 : Indo-Australian Hesperiidae: Description of new Genera, Species and Subspecies.
Entomologist 70(1): 16-19 (Part 9).

Evans, W.H.,1949 : A catalogue of the Hesperiidae from Europe, Asia and Australia in the British Museum (Natural History).
i-xix + 1-502, pls.1-35. London.

Huang, H.,1999 : Some new butterflies from China - 1 (Rhopalocera).
Lambillionea 99(4): 642-676.

Huang, H., & Xue, Y.,2004 : A Contribution to the butterfly fauna of Southern Yunnan (Lepidoptera, Rhopalocera).
Neue ent. Nachr. 57: 135-154, pl.11.

Uehara, J. & Maruyama, K.,2016 : The revision of Halpe arcuata group and description of two new species of Halpe Moore, 1878 (Lepidoptera, Hesperiidae) from Indochina.
Butterflies 73: 19-24.

♂, Lampang, Thailand.	♂, Lampang, Thailand.
♀+♂ (mating), Chiang Mai, Thailand.

1999.09.04 - 2025.02.28.