227. Lethe naga (The Naga Treebrown)

Number: 227

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe naga Doherty, 1889

Common name(s): The Naga Treebrown

Photography location: Tam Dao (Vinh Phuc Prov.)

Lethe naga (male), Tam Dao foothills (100m asl), 15th June 2016

Lethe naga (male), Tam Dao (900m asl), 23th June 2016
Note the rather plain underwing pattern with a row of postdiscal ocelli in line in spaces 2-6 of FW
Female is larger and with a broad oblique underwing white band on FW

221. Lethe philesanoides (The Interrupted Treebrown)

Number: 221

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe philesanoides Monastyrskii & Devyatkin, 2003*

Common name(s): The Interrupted Treebrown

Photography location: Huu Lien N.R. (Lang Son Prov.) 

Described from northern Vietnam (holotype: Cat Ba National Park/paratypes: Huu Lien Nature Reserve), This inhabitant of limestone forests is also known from northern Thailand. 

Lethe philesanoides is very similar to L. philesana Monastyrskii & Devyatkin, 2000. The two species can be distinguished by some details on the underwings pattern (see PDF documents below)*.

*Update January 2017: I sent the pictures below to A. Monastyrskii who answered: "Your specimen looks like L. philesana... however only genitalia analysis may confirms this".

Lethe philesanoides (male), Huu Lien (October 2016) - without flash (close to the "true colour" of the species)

Lethe philesanoides (female), Huu Lien (October 2016) - with flash

There are over 1100 butterfly species currently known from Vietnam. Approximately 7% of all species are considered as endemic to the Indochinese Peninsula (Vietnam, Laos, Cambodia and eastern Thailand) (Monastyrskii, 2010a). This is the case of Lethe philesanoides.

Voucher specimen, upperside (from Huu Lien)
Ground colour of both wings uniform deep velvet brown-black; apex indistinctly paler. 

Same individual, underside

Description of Lethe philesanoides (PDF document) here.

Description of L. philesana here.

213. Lethe verma stenopa (The Straight-banded Treebrown)

Number: 213

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe verma stenopa Fruhstorfer, 1908

Common name(s): The Straight-banded Treebrown

Photography location: Tam Dao (Vinh Phuc Prov.)

This is my 8th Lethe species seen in Vietnam... but 39 are listed in "Butterflies of Vietnam, an illustrated checklist" (Monastyrskii  & Devyatkin, 2016)... arghhh !!!

Lethe verma stenopa, Tam Dao, 25th August 2016
L. confusa and L. verma are very similar but the latter show HW weakly toothed at vein 4 (making the HW appear more rounded), HW subbasal whitish line zigzag, not as straight as that of confusa. 

212. Lethe mekara crijnana (The Common Red Forester)

Number: 212

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe mekara crijnana Fruhstorfer, 1911

Common name(s): The Common Red Forester

Photography locations: Tam Dao (Vinh Phuc Prov.), Ba Vi (Hanoi) foothills

I only managed some poor record shots (heavily cropped) for now... until the next time we meet!

Female (left) from Tam Dao, Sept. 2016 / Male (right) from Ba Vi, Dec. 2016

                                    In male, FW without subapical white bar beyond the cell

Lethe mekara, female, upperside (voucher specimen from Ba Vi, April 2017)

211. Lethe europa niladana (The Bamboo Treebrown)

Number: 211

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe europa niladana Fruhstorfer, 1911

Common name(s): The Bamboo Treebrown

Photography location: Ba Vi N.P. (Hanoi)

Well, after a number of years of searching but having little knowledge of the species, I finally clapped eyes on it: Lethe europa. I only managed a record shot (heavily cropped) as it was just too far out of reach. Still, I know where it is now and will search for it again next year (it is right at the end of its flight season now). It was worth all the effort - it really is a beautiful thing. For a naturalist, the most wonderful feeling is spotting a new species for the first time. I want to do cartwheels and backflips when I see something new. 

Northern Vietnam is a site of particularly high level of diversity for this genus, hosting over 80% of the known number of species (Monastyskii pp.32. in Anon, 2001).

In Greek mythology, Lethe, the river of forgetfulness, was one of the five rivers of the underworld, the other four being Styx (the river of hate), Acheron (the river of sorrow), Cocytus (the river of lamentation) and Phlegethon (the river of fire).

Male Lethe europa niladana, lower slopes of Mount Ba Vi, 4th December 2016
Female is similar but with broader oblique white band on FW

173. Lethe syrcis diunaga

Number: 173

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe syrcis (Hewitson, 1863)

Common name(s): ?

Photography location: Tam Dao (Vinh Phuc Prov.)

Lethe syrcis is a restricted range species (E. Himalayas, N. Indochina, S. China).
The subspecies diunaga has been described by Fruhstorfer in 1911 from Mount Mau Son (N. Vietnam, close to the Chinese border). This taxon is known from Laos, N. & C. Vietnam.

Lethe syrcis diunaga (Fruhstorfer, 1911) from Tam Dao, mid-May 2016

Hans Fruhstorfer (1866-1922) was a German explorer, insect trader and entomologist who specialised in Lepidoptera. He collected and described new species of exotic butterflies, especially in Seitz'sMacrolepidoptera of the World. He is best known for his work on the butterflies of Java. 

His career began in 1888 when he spent two years in Brazil. Next he spent some time in Ceylon, then in 1890 he went to Java for three years, visiting Sumatra. Between 1895 and 1896 he collected in Sulawesi, Lombok and Bali. In 1899, he went on a three-year journey to the United States, the Oceania, Japan, China, Tonkin, Annam and Siam, returning via India.  

Following his travels, he settled in Geneva where he wrote monographs based on the specimens in his extensive private collection. In taxonomy he made extensive use of the structure of the male genitalia. Fruhstorfer, in these years also studied Palearctic butterflies, Orthoptera and botany. 

Fruhstorfer's collections are deposited at the Museum für Naturkunde in Berlin, the Natural History Museum (BMNH) in London and the Muséum national d'histoire naturelle in Paris, as well as in many other museums.

Hans Fruhstorfer

172. Lethe chandica suvarna (The Angled Red Forester)

Number: 172

Family: Nymphaliidae
Sub-Family: Satyriinae

Species:  Lethe chandica Fruhstorfer, 1908

Common name(s): The Angled Red Forester

Photography location: Ba Vi N.P. (Hanoi)

Lethe chandica is mainly distributed across Southeast Asia and Southern China, reaching as far as Taiwan, Thailand, Myanmar, the Philippines and India. It is widely distributed in China, including Guangdong, Guangxi, Fujian, Chejiang, Yunnan and Tibet.

Male Lethe chandica suvarna (Ba Vi, July 2016)

So far I have seen this species at Ba Vi and Tam Dao, in both montane and lowland forests

Close-up on the nice hindwing underside pattern

Female Lethe chandica suvarna (dry season form), a worn individual found at Ba Vi on December 2016
The forewing white band is common to many Lethe females

166. Lethe insana (The Common Forester)

Number: 166

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe insana (Kollar, [1844])

Common name(s): The Common Forester

Photography location: Tam Dao (Vinh Phuc Prov.)

A male from Tam Dao, on April 30, 2016
The female show a wide white oblique band on both sides of forewings

163. Lethe vindhya vindhya (The Black Forester)

Number: 163

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe vindhya vindhya (C.& R. Felder, 1859)

Common name(s): The Black Forester

Photography location: Tam Dao (Vinh Phuc Prov.)

Individual photographed on March 2016 perched on a rock along a stream at Tam Dao foothills

Another specimen from Tam Dao, at ca 1000m asl, on April 2016, showing a more marked underwing pattern

5. Lethe confusa confusa (The Banded Treebrown)

Number: 5

Family: Nymphaliidae
Sub-Family: Satyriinae

Species: Lethe confusa confusa Aurivillius, 1898

Common name(s): The Banded Treebrown

Photography location: Ba Vi N.P. (Hanoi), Cuu Thac-Tu Son (Hoa Binh Prov.)

Northern Vietnam is a site of particularly high levels of diversity for this genus, hosting over 80% of the known number of species (Monastyskii pp.32. in Anon, 2001). 

L. confusa is the Lethe species I encounter the most in my habitual butterflies hunting grounds around Hanoi.

Lethe confusa, from Ba Vi
L. verma is very similar but HW weakly toothed at vein 4 (making the HW appear more rounded), HW subbasal whitish line zigzag, not as straight as that of confusa.

Lethe confusa, from Cuu Thac-Tu Son

Two specimens feasting on dung (Cuc Phuong, May 2016)