Graphium isander imparilis - Torres Strait

[steve]

This one is for Adam. We have recently been to several islands in Torres Strait, Queensland. There was a recent publication trying to unwind the G sarpedon complex and I would be grateful for your opinion of the specimens we collected on Mer ( Murray) and Dauan Islands. The Murray island specimen illustrated looks like G isander imparilis but I don't think that has been confirmed anywhere. What do you know about this ?

Steve

[Adam Cotton]

Firstly, can you clarify where Lockerbie is, please. I couldn't find that locality on Google Maps. I did find reference to "Lockerbie near Bamaga, Cape York". I would be interested to see photos of specimens from Dauan Island, if your place "Lockerbie" is not on that island.

I would also like to hear how much variation you found in the sarpedon group specimens from the same localities.

I will address your main question shortly.

Adam.

[Adam Cotton]

Having checked your photos with my specimens and some publications, I agree that the Murray Island specimen does look more similar to imparilis than choredon, however the only definitive way to tell is by checking the male genitalia.

Here is a figure showing the male genitalia of the sarpedon group taxa copied from Page & Treadaway, 2013:



The whole paper can be downloaded here:

www.naturkundemuseum-bw.de/sites/default/files/publikationen/serie-a/ans06-13_page.pdf

Sorry I can't give a more definitive answer, but knowing more about the variation of the specimens from each locality would give some clues. It would be interesting to know if the Murray Island specimens are consistently different from the ones from nearer Cape York. What do the Dauan Island specimens look like?

Adam.

[steve]

Thanks Adam. I have read that paper and still couldn't work it out. Lockerbie is 17 km north of Bamaga, Cape York as you said. I have specimens on the boards from both Dauan and Murray Islands and will post those when I can. On the surface though, the specimens from Dauan and Murray are consistent and are all like the one posted from Murray Island. Thanks for your help.

Steve

[Adam Cotton]

"On the surface though, the specimens from Dauan and Murray are consistent and are all like the one posted from Murray Island."

That makes sense. Dauan Island is so close to mainland PNG that I would expect the fauna to be the same too. Similarly Thursday Island is so close to Cape York that the specimens from there should be choredon. I would expect that imparilis will be found throughout the islands close to PNG, and across to Murray Island.

It would be interesting to examine the fauna of the islands in between and find out if there is a sudden change from one taxon to the other between islands as you move south, or if there is an area of overlap where both occur together.

Adam.

[Adam Cotton]

"I have read that paper and still couldn't work it out."

I am not surprised, as Page & Treadaway probably didn't see many specimens from the Torres Strait Islands (if any). They don't mention Torres Strait at all.

There is still a lot of research to be done on the sarpedon group (including whether all of the species they delimited really deserve specific status), and your data on Torres Strait will be very useful. I hope you will have a chance to visit other islands to sample the fauna there.

Adam.

[wollastoni]

I have met Graphium sarpedon in Japan and in West Papua (not sure if those are still called sarpedon). It is a splendid, common and fast flying Papilionidae !

[Adam Cotton]

The West Papua sarpedon was separated by Page & Treadaway with PNG and the Solomon Is taxa into Graphium isander, and the Papuan subspecies is imparilis.

The Japanese butterfly still belongs to Graphium sarpedon and is ssp. nipponus.

Adam.