Butterflies of Vietnam: Trip to Cuc Phuong N.P.

The Cuc Phuong National Park – one of Vietnam’s most beautiful and accessible tropical forests, allows visitors the pleasure of driving comfortably through the park. The road (20 km) snakes along a valley, bordered on both sides by dense primary forest with an amazing diversity of plants, mature trees and animals as well as a number of well-maintained trails to accommodate hikers. Typically the forest canopy closes above the road but occasionally a large break allows light to penetrate to the road surface and the forest floor. These clear areas, with full sunlight intensity, provide the proper conditions for remarkable aggregations of a diversity of butterfly species. Ever so often, at mudpatches in these clearings large assemblages of butterflies burst into a cloud of colours – white, orange, blue, green, and black - when disturbed by approaching vehicles or hikers.

In 1963, at the height of the war, President Ho Chi Minh inaugurated what is now the national park, with the words: “Forest is gold. We must conserve it well. Destruction of the forest will lead to serious effects on both life and productivity.” So Cuc Phuong National Park is now the star of conservation in Vietnam. Just 130km from Hanoi, with daily scheduled buses, accommodation at the edge of the Park as well as in the centre ranges from the modestly luxurious to basic – catering for any budget. Good restaurants are available. Very few similar forests allow such comforts.

The Cuc Phuong butterfly fauna is one of the best studied in Vietnam. The present list of verified species has passed 400 thanks to the research by Ikeda et al. (1998-2002), Hill & Monastyrskii (1999), and Hao et al. (2005). But it's likely that dozen of species remain to be discovered. A total of 450 species is a safe estimate. This is 40% of the known butterfly fauna of Vietnam. So the number of species of butterflies in this not very large forest (220 square km) is the equivalent ot the entire butterfly fauna of Europe. This is biodiversity writ large!

Three weeks ago I was back to Cuc Phuong, a place I have visited many times for birds, but only a few times for butterflies - yes, butterflying and birding are very hard to practice at the same time, and even more so if you are photographer (you will have to change lens all the time !). I stayed there 1,5 day. By the end of the first day I saw around 80 species, and I added 25 more species the following morning. But it's possible to spot more than 100 species in the park on a single, good day - but you will have to let your camera in the bag and use more the net!

Checklist of the ca 105 species spotted at the location (1,5 day, 20/21th May 2017):

Papilionidae

Chilasa paradoxa +
Papilio nephelus +++
Papilio helenus +++
Papilio polytes +++
Papilio memnon +++
Papilio protenor +++
Papilio paris ++
Graphium sarpedon ++
Graphium doson ++
Graphium agamemnon +
Graphium eurypylus ++
Graphium chironides +
Graphium macareus ++
Graphium xenocles ++
Lamproptera curius ++
Lamproptera meges ++

Pieridae
Leptosia nina +
Prioneris thestylis ++
Pieris canidia ++
Appias lyncida +++
Appias albina +++
Appias galba +++
Appias indra +++
Cepora nadina +++
Cepora nerissa +++
Hebomoia glaucippe ++
Ixias pyrene ++
Eurema andersoni ++
Eurema hecabe ++
Eurema blanda ++
Catopsilia pomona +++

Nymphalidae
Danaus genutia ++
Parantica aglea +
Parantica melaneus +
Euploea mulciber ++
Euploea core ++
Euploea tulliolus +
Euploea sylvester ++
Tirumala limniace +
Elymnias hypermnestra +
Lethe confusa +++
Penthema darlisa +
Coelites nothis ++
Mycalesis spp. +++
Mycalesis malsara ++
Ypthima spp.+++
Faunis canens ++
Stichophtalma fruhstorferi +
Stichophtalma suffusa +++
Acraea issoria +
Ariadne ariadne +
Athyma selenophora +

Athyma nefte +
Cupha erymanthis ++
Rohana sp. +++
Cethosia cyane +
Cethosia biblis ++
Cirrochroa tyche +
Vagrans egista + +
Hestinalis nama +
Symbrethia lilaea +++
Symbrethia hypselis +
Juniona almana ++
Juniona atlites ++
Hypolimnias bolina ++
Cyrestis thyodamas +++
Cyrestis cocles +++
Cyrestis themire +++
Chersonesia risa ++
Vindula erota +++
Neptis clinia +++
Polyura athamas +++
Charaxes bernardus ++
Cynitia lepidea +
Tanaecia julii +

Riodinidae
Zemeros flegyas ++
Abisara echerius +

Lycaenidae
Curetis sp. ++
Jamides celeno +++
Heliophorus delacouri ++
Megisba malaya +
Udara cf. dilecta ++
Acytolepis puspa +++
Tongeia potanini +
Catochrysops strabo +
Ionolyce helicon +++
Anthene emolus +++
Prosotas dubiosa +++
Prosotas nora +++
Hypolycaena amasa ++
Yasoda tripunctata +

Hesperidae
Bibasis vasutana +
Abraximorpha davidii ++
Tagiades sp. +
Odontoptilum angulata ++
Arnetta atkinsoni +++
Pelopidas conjuncta +
Polytremis lubricans +
Astictopterus jama ++
Ancistroides nigrita +
Koruthaialos sindu +
Potanthus sp. ++
Parnara sp. ++

(Abundance : + 1-2 specimens, ++ 3-5 spec., +++ more than 5 spec.)

Chilasa paradoxa telearchus - an excellent mimic of Euploea species
Again this species eluded me - couldn't get a close-up shot arghh...!

Mudpuddling congregation of Appias, mostly albina

The abundance, beauty and diversity of butterflies in the park are among the visitors’ most vivid memories of Cuc Phuong National Park

Colorful puddling party with, from left to right, Appias galba, Cepora nerissa & C. nadina
Note the the difference of color pattern of the two A. galba - the reddish 'form' is rarer

Hebomoia glaucippe
An obvious species in flight, but very cryptic at rest

Catopsila pomona, male f. alcmeone

Coelites nothis

Underwing pattern very 'Satyrin-style', but that's not the case of the upperwings which show a stunning and unexpected blue tinge

Mycalesis malsara

Stichophtalma suffusa tonkiniana (left) & S. fruhstorferi (right) - note the completely fused submarginal black markings in the former. At Cuc Phuong, the two species occur sympatrically.

Stichophtalma fruhstorferi
Note on UnH the small streak (red arrow) inside the discal cell. In Vietnam, only S. fruhstorferi and S. uemurai show this feature

Tanaecia julii - pair in copula

Cethosia biblis, male

Acraea issoria

Chersonesia risa

Eurema andersoni puddling with Cyrestis themire

Charaxes bernardus puddling with Polyura athamas
Charaxinae (in Vietnam, genera Charaxes and Polyura) feeding from dung, carrion and rotting fruit but rarely (if ever) 'nectar' at flowers

Butterflies feasting on some fresh human dung (Charaxes sp., Polyura athamas, Vindula erota, Lethe confusa)
Some butterflies have slightly less salubrious habits than we like to think...

Polyura athamas

Abisara echerius

Curetis sp. (bulis and acuta are both present at Cuc Phuong, identification from underside only is tricky)

Acytolepis puspa

Ionolyce helicon

I thought it was a new species for my personal list but I couldn't find anything in the Vietnam's Polyommatinae list that matched up. A. Monastyrskii solve the mystery: it's 'just' an aberrant female specimen of (very likely) Pseudozizeeria maha !

Prosotas nora perched on my finger - very tiny indeed...

Tongeia potanini

Two species of Tongeia are known from Vietnam (Monastyrskii & Devyatkin, 2016): T. potanini (subsp. potanini in the North, subsp. umbriel in Central VN) and T. ion (North only)

Yasoda tripunctata

Bibasis vasutana - my favorite butterfly of the trip (I really love Coeliadinae Hesperids!)

Odontoptilum angulata mud-puddling at moist soil

Koruthaialos sindu
The genus Koruthaialos comprises of 4 species, all of which being limited to the Oriental region. In Vietnam 3 are recorded - rubecula, sindu and butleri.