The last species in the genus Allancastria, alphabetically, is also the most obscure. Again, the obscurity of Allancastria or Zerynthia louristana is partly due to uncertainty about whether it really qualifies as a distinct species. It is found only in western Iran, hence its name. It can look just like A. cerisyi, or so different that at one time it was classified in a different genus as Archon bostanchii. (The Archon genus are brown and tailless.) However, it was found to be able to hybridize with other Allancastrias rather than with Archons. It may have more of a brownish tone to its blackish and whitish markings than the other Allancastria species have, or not. Like the other species in the genus it's variable. Few photographs are available; the individuals photographed have swallowtail-type wing structure but lack the tails. Bodies are furry. Compared with the big American swallowtails and the huge tropical birdwings, the animals are very small.
This individual is more colorful than several of those chosen to illustrate the species. It's also still alive; many of the few sites that do illustrate this species show poor little dead specimens on pins. Because it's rare, many people seem to want dead specimens on pins. One site even offers a dismembered specimen for sale, the collector selling each wing, the head and thorax, and the abdomen separately. At least one can hope that these killed specimens were among those that, according to Jangala magazine, have been successfully reared in captivity.
(You can read the whole relevant issue of Jangala online, in Spanish, at https://issuu.com/jangala/docs/180320 .)
Because these butterflies have always been rare and relatively little is known at them, they're not on the international endangered species lists (yet), but naturalists are watching them. The species does not have a lot of numbers to lose.
Some individuals in this species have white forewings with a few black markings, and pale gray or drab hindwings with black or dark drab markings. A British visitor to Louristan described them as "pale yellow...laced lightly with patterns in black and red." The undersides of the wings are often drab. Females are slightly larger than males.
Mother butterflies in this species are not careful to place only one egg on a leaf. The eggs are round and may look white, creamy, or colored. Six or eight eggs may be placed together.
Photo by Mrehssani.
The caterpillar (note its resemblance to the deyrollei caterpillar) has a swallowtail-like shape, with a, slightly humped back. From some angles the markings might suggest the face of a snake or lizard. Like the other Allancastria species, the caterpillars eat vines in the genus Aristolochia; they may be able to use two or three species of these vines. The individual photographed is obviously showing no interest in those other eggs; groups of eggs laid close together are an indication that insect larvae are not shell eaters and won't be tempted to cannibalize one another.
Photo by Mrehssani, copyright, used under Fair Use.
The more typical top view of the same caterpillar is at https://es.dreamstime.com/alancastria-louristana-butfly-caterpillar-larvas-o-oruga-de-alimentadas-con-aristolochia-sp-una-mariposa-rara-y-end%C3%A9mica-image178753462 .
While it lasts, there's also a painting, with n unobtrusive A. louristana caterpillar, being sold in aid of a conservation group: https://www.artistsforconservation.org/artists/19713/portfolio/price-greed-15346 . This link is likely to bebroken soon.
The caterpillars pupate during the winter. According to the Jangala article cited above, when weather conditions are "unfavorable" they can stay in their pupal shells for two or even three winters, survive, emerge, and fly in spring.
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