Tersa sphinx or other moth?
February 23, 2010
Okay, so at first I thought that I had readily identified this as a Tersa Sphinx, however they aren’t even listed here in Hawaii on the Insects of Hawaii website (not that it doesn’t mean they don’t exist here). So, then I decided to look a little further and realized that the Tersa Sphinx has black and white coloration on the lower wings. I went back outside to try to bother my newfound subject into showing me his/her wings, Took some effort, but to my surprise they were orangey pink not black and white. So now here I sit stumped and confused. It was approximately 1.5-2 inches long, and is sitting on a fire hose connection under the outside light. Could it possibly be Hippotion boerhaviae or maybe perhaps Hippotion rosetta? How are you supposed to be able to tell the difference in these moths? Any help would be greatly appreciated.
We are nearly certain your moth is a Yam Hawkmoth, Theretra nessus, and it is depicted on Bill Oehlke’s excellent website. Bill only has one image of a living moth, and your moth has light markings on the thorax that differ from the identified image. We checked a second website, and the Sphingidae of the Eastern Palaearctic has numerous living specimens, but again, they all lack the light stripe on your individual. We are copying Bill Oehlke on this response in the hope that he can either confirm our identification, or provide a correct identification. We hope you will also provide Bill with additional information as he is compiling comprehensive data on Sphingidae sightings, and he may also want to post your photos on his site.
Bill Oehlke makes a correction
Here is message I sent to Tina:
Daniel Marlos asked me to have a look at your Sphingidae images from Hawaii.
There are no known resident populations of Hippotion species on Hawaii, but I agree that your pictures show either H. rosetta or H. boerhaviae
Sphingidae are known to fly great distances, but your specimen seems to be in very fine shape, not at all warn from a long flight.
I suspect it came in on one of the cruise ships. It may have alighted on one of the ships in the South Pacific, attracted by lights, and may have remained there for a trip to Hawaii.
It also may have come in on an imported shipment of potted plants. They don’t always get inspected as well as they should, and if the larva had already gone underground, it would have gone unnoticed until it emerged about fourteen days later as a moth in a new location. Also possible that someone found the larva or pupa while digging, wanted to see what it would become, put it in a jar, hopped on an airplane and flew to Hawaii.
While on vacation the moth emerged and you photographed it.
You are right, it is not Xylophanes tersa; nor do I think it is Theretra nessus.
Determining identifications for many look-alike Sphingidae species can be difficult. As your moth is an obvious stray or import, we do not know its origin. Sometimes seeng the hindwing helps, sometimes seeing the ventral surface works.
There aere some species so similar that DNA barcoding or analysis of genitalia are necessary to tell them apart.
I wanted to say thank you so much for the quick responses. I did find Hippotion boerhaviae listed on the species index for Hawaiian insects on the insects of Hawaii website, though it does say that they are not native. I don’t know if they can be readily found here, but I am assuming that is what it means. As to Bill Oehlke using my photos for his website, I would be more than honored, and if he needed any additional data I would be more than willing to provide it as well. Again, thank you all for such speedy and informative responses.
The Sphingidae of the Eastern Palaearctic website indicates: “Adults can also travel long distances, either voluntary or involuntary. Bell & Scott (1937) once saw hundreds come on board a ship sailing between Aden (Yemen) and Bombay (India) during a cyclone.“