InsectNet forum

For your consideration is a male specimen of Troides magellanus collected in April of 2023 in Aurora Province, Philippines. This species is my personal favorite - I hope that viewing the images that follow will adequately justify my opinion. It is a truly magnificent species of birdwing. Females are among the largest butterflies found in the Philippines, along with its cousin, Trogonoptera trojana. In addition to T. prattorum, it is one of two known butterfly species that make use of limited view iridescence to produce those spectacular opalescent blues and greens when the hindwings are viewed from an oblique angle.

Regrettably, I do not have more specific collection data for this specimen, as it was purchased (along with a matching female) from a dealer. Of course, there is always the possibility that what limited data I have is outright fabricated, but nonetheless, it remains a highlight of my collection. The specimen arrived papered, and the abdomen seemed to have been flattened in the paper triangle, so I had to incise the ventral abdomen in order to stuff it with cotton. A 'crease" remains visible on the dorsal side. Similarly, the antennae were not as cooperative as I had hoped, and though I had straightened them perfectly on the spreading board, they warped into a more natural (lifelike?) contour shortly after I removed the specimen from the board.

Personal gripes with pre-dried specimens aside, I have since sought the advice of an acquaintance who has had success in collecting this species on Cebu island, which is where I live. Apparently, there are a few spots about an hour's drive from the city where these winged jewels still fly. I hope to follow up on that tip over my semestral break in December.

I think it is better not to try to flatten the antennae of butterflies if they are not naturally straight. Some species have curved antennae and some straight, so spread them accordingly.

Adam.

PS. Superb species!!!

Thank you!

adamcotton wrote: Wed Nov 20, 2024 7:55 pm I think it is better not to try to flatten the antennae of butterflies if they are not naturally straight.

I generally try to straighten out my antennae, as I find it more visually pleasing, in addition to being a fulfilling challenge. My reasoning is that it's generally understood that live Papilionids have curved antennae anyway.

I do understand the merit of leaving the antennae curved - sometimes, I set them in such a manner that they appear straight when viewed from above, but retain their natural curvature when viewed from the side. The T. rhadamantus in my display picture is one such example.

While on the topic of T. magellanus, I would like to ask if anyone knows if there is a way to visually distinguish the nominate subspecies and T. magellanus sonani? While a specimen's collection data would more accurately and definitively put that matter to rest, I was wondering if there was a consistent/reliable way to differentiate the two by simply viewing a specimen.

From the photos I have been able to find online, it seems that subspecies sonani tends to be "shorter" i.e. that the forewings are smaller in terms of measurement from apex to dorsum. Additionally, from my cursory viewings, subspecies sonani features more ovate forewings, in contrast to subspecies magellanus, in which the hindwings are noticeably more falcate.

I'm also aware of the existence of two other proposed subspecies as per Okano and Ohkura (1978) namely T. magellanus apoensis and T. magellanus leytensis, though I believe they have also been synonymized with the nominate subspecies, despite still being listed as valid on Wikispecies among other online sources. I'm mainly interested in the differences (if any) between the T. magellanus that occur in the Philippines versus those that occur in Taiwan.

Looking for insight on this - thanks!