Thursday, 4 June 2015

Bayadera species - more confusion

Over the last few weeks I was lucky enough to find at least 5 Bayadera species. I already posted on Bayadera continentalis at Pia Oac. In the meantime I have also been able to capture a female, on May 20.

Interesting pattern with heart-shape laterally and a large elongated spot over the humeral suture. Bayadera continentalis female

Scan of the same female, displaying a distinct brownish wash to the wings
The next species that caught my attention was Bayadera nephelopennis, which apparently is not uncommon in the Sa Pa region. This species can easily be confused with Bayadera bidentata. Both have blackish males with a little pruinosity. B. bidentata is somewhat smaller and the females are in fact rather different in pattern, as I hope to show further on. Anyway, on May 18 I saw both a female and a handful of males in Sa Pa and again several males and a female on May 25.

Female Bayadera nephelopennis in hand

The dorsum of the thorax is quite distinctive. It has broad lines along the dorsal carina, but nothing over the humeral suture.
Another female on May 25

A male on May 18, showing the quite unicolorous appearance
But a pretty face, although this pattern seems shared by many species
 On May 25 I spotted yet another species at Sa Pa that I identified as B. hyalina. However, it does not have dorsal lines on the thorax and several other characteristics of a species. Whether that is an indication of variability or indicates a possible different species needs to be resolved at some stage, preferably through DNA analysis.

Bayadera hyalina (or possibly closely related species?)
Scan of dorsal aspect
 On May 23 weather was cloudy over Pia Oac, so I checked a stream further down and bumped into a whole bunch of Bayadera serrata.  A female in tandem showed herself fleetingly and was quite yellow, but I could not get a photo of her.

Bayadera serrata, male. A beautiful and distinctive species
Brightly coloured thorax and face
And distinctive bird-beak appendages
And finally the last species was Bayadera bidentata. Surprisingly this species showed up with several males and females at Xuan Son on May 30, where we had completely failed to see it previously!

Male Bayadera bidentata, with quite a bit of pruinosity on the thorax contrasting with the black dorsum

The usual pretty face

The female B. bidentata is rather different from B. nephelopennis. It has an irregularly shaped marking over the humeral suture, which is lacking in that species, and reversely misses the lines along the dorsal carina.
 Not to make this posting excessively long, I will publish the differences on the appendages between these species in another post.

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