Alpine black swallowtail

Papilio maackii, the alpine black swallowtail, belongs to Papilionidae. [1]

Predominantly dark wings contain green and blue reflective regions. Their reflected hue varies with illumination angle, as measured in the wing-scale optical study. [1][3]

The Taiwanese fauna records the species in East Asia and classifies a single male collected in Taiwan in 1935 as an accidental occurrence. Japanese experimental material came from Honshu and Kyushu. [1][4]

In the host-selection study, females accepted Phellodendron amurense, the Amur cork tree, for egg laying. Larvae of both P. maackii and P. protenor developed well on this plant in the laboratory, although the latter species did not naturally use it in the study setting. [2]

In Japanese laboratory trials, tested females showed stronger host-searching and egg-laying responses to the three non-Citrus plants than to Citrus deliciosa. The tested alternatives were Phellodendron amurense, Zanthoxylum ailanthoides and Orixa japonica. [4]

The green and blue wing regions have scales with microscopic ridges and cross-ribs. In the study, the reflected colour shifted toward shorter wavelengths as illumination changed from perpendicular to more oblique angles. The authors’ simplified chitin–air models linked differences in scale geometry to the green and blue reflection spectra. [3]

Phellamurin, a compound in Phellodendron amurense, stimulated egg laying in P. maackii but deterred P. protenor in the host-selection experiment. The same plant compound therefore had opposite effects on these closely related butterflies. [2]

The green and blue regions reflect different portions of visible light. Changes in illumination can shift the apparent colour and brightness of these scaled surfaces. [3]

Green-blue flat colour regions preserve the reflective areas within dark wings. Bold contours define the silhouette and restrained internal lines retain the pattern boundaries. [1][3]

Protect scaled wing surfaces from handling and abrasion. Keep the specimen in a stable enclosure away from direct sunlight, heat and moisture. [5]

Why does the reflected colour change with angle? The optical study measured a shift toward shorter wavelengths under more oblique illumination and linked the reflection spectra to microscopic scale geometry. [3]

What stimulates egg laying on Amur cork tree? Phellamurin stimulated P. maackii females in the host-selection experiment, while deterring P. protenor. [2]

The Taiwanese fauna records regional occurrence. Chemical-ecology studies examine host acceptance and plant volatiles, and the optical paper reports wing-scale architecture and angular reflection. [1][2][4][3]