As regular readers know by now, there are a lot of large butterflies that live in southern Asia and have at least partly red bodies and at least partly black wings. All of them are in the swallowtail family, so at first scientists put them in the genus Papilio. That genus became crowded, and these Asian butterflies share several special traits the other swallowtails don't have, so the genus name Atrophaneura was created just for them. As we've seen this winter, there were still a lot of species in the genus Atrophaneura, so recently some of them have been reassigned. The genus Byasa was created for butterflies in the Atrophaneura group that have long, thin hind wings that can be spread out into an x shape, in which position the butterflies reminded some people of windmills. Other butterflies in this group, because of their red to pink colors, were called Roses...and Byasa latreillei, as it is now officially called, has the English nickname of Rose Windmill. Its markings seem to mimic a more common species now classified as a Pachliopta or Rose.
Because it looks like other species the Rose Windmill has often been seen as a subspecies--of Atrophaneura philoxenus, or minereus--but it is now generally recognized as a distinct species. Its species name commemorates one of the old naturalists, Pierre Andre Latreille.
In some of its habitat, this butterfly has the traditional name kupu-kupu.
Photo donated to Wikipedia By Balakrishnan Valappil - NE_Pa_Rose Windmill Atrophaneura latreillei_13 April 2008_Namdapha, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=67295248
As with the other butterflies in this family, the wings can look black or fade to drab with darker drab veins, and the body can look scarlet or crimson or fade to a pink or orange shade. Males and females look almost alike. On close observation, females have a few extra spots on the hind wings. Males, instead, have a fold in the inner edge of the hind wing from which they release a characteristic scent, sometimes noticeable by humans, that identifies this species. Despite their different wing shape, from a distance or in flight they look like some of the other black-winged, red-bodied swallowtails, the Common Rose (Pachliopta aristolochiae, previously discussed at this web site) or the Common Mormon. Since these species don't crossbreed, they use scent to recognize each other. Females in this group average slightly larger than males. All of them are large butterflies, with wingspans over four and often over five inches.
Even living individuals can show this faded coloring.
The Rose Windmill is less common. It is widely distributed across Afghanistan, Bhutan, China, India, Myanmar, Nepal, Pakistan, and Vietnam, but flies only in May and June, only at elevations between 5000 and 9000 feet. It is not usually considered especially rare or endangered, but at least one subspecies is protected by law in India, and Bimal Raj Shrestha identified it as potentially endangered in a document sold through Researchgate.net. The protected subspecies, Byasa latreillei kabrua, is most noticeably different from the more common subspecies because it is smaller, wingspans less than five inches.
The black and faded-black wings of this group of butterflies suggested funeral attire to naturalists of past generations. However, unlike some of the bright-colored swallowtails, the butterflies are pollinators rather than composters, so they're not a typical part of woodland animal "funerals." They are attracted to flowers of sizes proportionate to their own size, lantanas and hibiscus and other semitropical forest specialties.
While the reproductive processes of moths and butterflies are one of the ways experts identify confusible species, they're not something normal humans want to think about. Suffice it to say that most of these insects mate in positions that protect their wings. If they embrace face to face, they cling to a twig while doing so. There is, however, a Youtube video documenting that at least some Byasa latreillei actually lie down on the ground, in a way few butterflies ever willingly do. The pair whose private moments were caught on video rolled about in the sand with little concern about possible wing damage.
After mating, large female butterflies usually do a lot of flying. Unlike some moths that lay all their eggs at once, swallowtails usually lay their eggs by ones, and look for a fresh new leaf, at least a few yards apart if not on completely separate plants, to ensure each caterpillar will find enough leaves to eat without harming its host plant. The person who documented Rose Windmills' mating process failed to document what the eggs look like or where they are laid. Swallowtail eggs are usually visible to the naked eye, shaped like tiny beads, but no one seems to have photographed or even described the eggs of this species.
The caterpillar is similar to others in this group. It can be described as aubergine or brownish purple, covered in bumps for maximum bird-repellent effect, with a white "belt." It eats plants in the genus Nepenthes perhaps more than the other swallowtails' favorite genus Aristolochia.
The pupa has an orange-ish color and that wide, flat, dead leaf shape that other Roses and Windmills have, and is said to squeak when disturbed, as some of the sphingid moth pupae do. Moths and butterflies have no vocal organs. They "talk" to one another mostly through scent, releasing subtly different odors (only a few of which humans notice) that announce which individuals are ready to mate and which food plants have been claimed. However, when they encounter possible predators, some of the larger ones can "scream." When they take a deep sharp breath, a hiss or squeak can be produced by air rushing through the breathing pores along their sides.
In the past some "collectors" gave these butterflies reasons to scream when approached by humans. The primitive way of studying butterflies was to collect dead bodies, document where they'd been, and try to learn something by comparing size and colors before the colors faded and the bodies attracted the beetles that normally compost butterfly carcasses. This morbid and unhygienic approach to science often motivated naturalists to kill healthy butterflies, and they learned that, while pinching the thoracic segments of smaller butterflies usually kills them, pinching swallowtails without actually crushing their bodies only hurts them enough to immobilize them for a few minutes. Of course, now that we can learn more from live photographs of butterflies than from decaying bodies, no right-minded person wants to kill them. Butterflies live only a few weeks. Let them enjoy the time they have. Auction sites still list dead bodies of tropical butterflies for sale, but we should never pay for a dead butterfly.
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