This butterfly, which belongs to the knight butterflies (Papilionidae) in the animal kingdom, was only discovered in 1965 by Suguru Igarashi on Luzon.
Papilio chikae is the most endangered and most sought-after by collectors and therefore also the most expensive swallowtail in the world, along with the Queen Alexandra's birdwing (Ornithoptera alexandrae) from New Guinea. There are now two subspecies, Papilio chikae chikae from Luzon and Papilio chikae hermeli from Mindoro. The genus name has now been expanded with a subgenus "Achilides".
It is distributed within a small forested area in the Philippines. Its range extends to the mountainous area around Baguio and Bontoc in the Southern Cordilleras flying above 1500m and higher around Mt. St. Thomas on the island of Luzon. The butterfly is considered a glacial relic and is counted in the Papilio paris group because of the bright wing colours and colourful scales pollination. The butterfly flies at high altitudes within clearings, paths and more open forested areas with Benguet pine (Pinus insularis), host to the still largely unknown caterpillar, presumably of the genus Euodia spp. (Rutaceae). The butterflies feed on a wide variety of flowers and mineral-rich wetlands and, with the exception of a short break, fly from November to early January.
The butterflies are true miracles of colour. The basic colour is black, covered with scattered green scales. A large spot in the apical area is green when pupating in the winter and blue in the summer, the red lunettes can be well developed and have purple inner edges.
The spring form of Papilio chikae flies from January to early April and the summer form from mid-April to November. The summer form is larger, while the spring form has lighter colours. This seasonal variation in a species of montane subtropical habitat indicates its status as a relict continental species. This endemic butterfly species was probably spread south from China and Taiwan during the last Ice Age. Then, when water collected as ice at the poles and sea levels fell significantly, the ice retreated and sea levels rose again, Papilio chikae was left as an isolated species (glacial relict).
In the course of a tourist development to gain accessibility to the holiday resorts of Baguio and Bontoc, a road was created in the central cordillera which, unfortunately, also reaches the flight area of Papilio chikae at an altitude of about 1000 m. This resulted in ideal catching grounds for collectors. Since the butterfly also has a slow flight and likes to be baited with flowers, it is easy to catch. A collection is therefore inevitable. Many Japanese collectors finance their journey home with a butterfly sale at 400 to 700 dollars.
Despite being included in category A1 (CITES) of the Washington Convention on the Protection of Endangered Species, there are no serious conservation efforts. The protection of the butterfly can only be realised by legally enforcing high fines and if the ban on possession applies to Europe and the rest of the world. Philippine state authorities, on the other hand, promote deforestation and mining in the area, also for economic reasons, and thus destroy important butterfly habitat.