A multi-frocked courtesan!

The Courtesan (Euripus nyctelius) male
The Courtesan (Euripus nyctelius) male

What stands out most about this butterfly are its bright yellow eyes.  I don’t know what function the yellow has, if any, but it offers a beautiful contrast to the black, white and brown colours of the rest of the butterfly.  I’m not sure how it got its name: The Courtesan (Euripus nyctelius) .  It may relate to the fact that the females of this species come in a variety of different forms (i.e. they are polymorphic), or it might be because it appears rather well dressed and courtly!

The Courtesan (Euripus nyctelius) male tasting a leaf surface
The Courtesan (Euripus nyctelius) male tasting a leaf surface

The butterfly, which existed for millions of years without the benefit of a name, was first named, that is to say given a scientific name, by a gentleman called Edward Doubleday Esq, in 1845 (1). It was originally called Diadema nyctelius. Reading the 1845 Volume 16(1) of the ‘Annals and magazine of natural history’ – which is wonderfully easily available in this digital age (1) – makes me think that he did not actually see a live specimen, because there is no mention of the yellow eyes!  The insect was described as ‘being in the collection of the collection of the British Museum’, so perhaps it was collected in somewhere in South East Asia and sent to the museum for identification.

The Courtesan (Euripus nyctelius) male DCD 2

The Courtesan is relatively rare in some places, such as Singapore – which is perhaps not surprising! (see links 2, 3) – but in Thailand, where I took these photographs, it is listed as being common (4).  Unfortunately, I did not see – or photograph – any of the females of this species, which I saw in Doi Chiang Dao, Chiang Mai Province, Thailand.  The sexes are dimorphic (i.e. the males and females look different!) and the females are polymorphic (i.e. they come in different forms!).  There are also different types of female forms in different places, which would make this species an excellent subject for an in-depth study (has anyone done it I wonder?).  There are at least five different female forms (black, dark brown, iridescent blue etc.) which mimic different models; meaning that they look like completely different butterflies.  Some female forms mimic the male of one species (such as the Magpie Crow, Euploea radamanthus), whilst other forms mimic the female of the same species.  Other forms mimic different species altogether.  It is worth mentioning that this butterfly is in the family Nymphalidae, wheras the species which it mimics are in the family Danaidae; in other words they are completely different in terms of their taxonomic position.  Yet the female Courtesans have evolved to mimic the different butterflies, the so-called models.  This form of Batesian mimicry – going by the mouthful of a term, ‘female-limited mimetic polymorphism’ – is sustained by the fact that the butterflies that are being mimicked are poisonous, so looking like the distasteful models (which predators such as birds have learnt to avoid) offers a clear selective advantage to the female mimics.  The situation is slightly more complicated in some species which also have non-mimetic females (!), but in this species, all of the female forms are mimetic.

1) Biodiversity Heritage Library. http://www.biodiversitylibrary.org/item/19483#page/206/mode/1up

2) http://butterflycircle.blogspot.co.uk/2008/08/butterfly-of-month-august-2008.html

3)  http://butterflycircle.blogspot.co.uk/2008/08/butterfly-of-month-august-2008.html

4) Pisuth Ek-Amnuay (2012) Butterflies of Thailand 2nd Ed. ISBN-13: 9786162079887

The thousand year old rose

Rhododendron arboreum subsp. delavayi flower on Doi Inthanon, Thailand
Rhododendron arboreum subsp. delavayi flower on Doi Inthanon, Thailand

This rhododendron is known as the ‘the thousand year old rose’ in Thailand, and for all I know they really do grow for a millennium.  The Latin name is Rhododendron arboreum subsp. delavayi and the plant produces lovely red flowers during the winter (January and February).  R. arboreum subsp. delavayi is not unique to Thailand but is also found in India and Myanmar.  The plants grow at high altitudes, typically on the tops of mountains in Thailand, such as Doi Chiang Dao and Doi Inthanon – Thailand’s highest mountain – where I took these pictures.  It is difficult to predict the best date to see the flowers in Thailand; these photos were taken at the beginning of February this year (03/02/14) and the flowers were probably slightly past their peak.  Nevertheless, they remain impressive and have a certain regal presence.  I understand that their status is vulnerable and most people respect their uniqueness and do not pick them; indeed it is considered bad luck to try and plant them in your garden in some cultures.  The trees are however, used for incense in some places, although this is presumably a sustainable use.  On Doi Inthanon in Chiang Mai Province, these trees can be see on both the Kew Mae Pan Nature Trail and the Ang Ka Nature Study, described in previous blogs, but only for a relatively short period (Jan/Feb) each year.  The rhododendron trail on at Doi Ang Khang is another good place to see them.

Rhododendron arboreum subsp. delavayi on Doi Inthanon, Thailand
Rhododendron arboreum subsp. delavayi on Doi Inthanon, Thailand
Flowering  Rhododendron arboreum subsp. delavayi tree on Doi Inthanon. Thailand
Flowering
Rhododendron arboreum subsp. delavayi tree on Doi Inthanon. Thailand

A wandering snowflake

The Psyche (Leptosia nina)
The Psyche (Leptosia nina)

This little butterfly is a member of the family Pieridae, and has a wide distribution which covers Southeast Asia and the Indian subcontinent. I took this photograph in northern Thailand. It was reportedly given the lyrical name of ‘wandering snowflake’ by a Victorian entomologist called Charles Lionel Augustus de Nicéville, who wrote a three-volume treatise on The butterflies of India, Burmah (sic.) and Ceylon. These books can still be read online (1).  It’s common name is Psyche, or a little spirit.  It reminds me of another little white pierid butterfly, The Wood white (Leptidea sinapis), which also has a wide distribution, across Europe, the Middle East and Central Asia.  I took this photograph of two Wood whites – perhaps a male and female as they appear to be exchanging something via their proboscis – in Spain.  Another pair of summer snowflakes!

Wood whites (Leptidea sinapis)
Wood whites (Leptidea sinapis)

1) Niceville, Lionel de (1886) The Butterflies of India, Burmah and Ceylon. Volume 2. Calcutta Central Press, Calcutta (https://archive.org/details/LepidopteraNiceville2)