2018 Volume 69 Issue 1 Pages 33-43
Seasonal （spring and summer forms） and sexual differences in the reflectance and scent scale substances of the wings of the green-veined white butterfly, Pieris napi japonica （the Japanese subspecies） were examined by scanning electron microscopy （SEM）, spectrophotometry, and gas chromatography. SEM observations revealed that the white scales of the dorsal and ventral wings of spring form butterflies of both sexes had beads that presumably absorb predominantly ultraviolet （UV） light. However, in the summer form, only the white scales of males had beads, whereas the white scales of females lacked beads. No seasonal differences were observed in the UV reflectance of male dorsal wings. In contrast, the UV reflectance of summer form female wings was higher than that of spring form female wings. Scent scales （androconial scales） were observed only on the dorsal wings of the male spring and summer forms. The scent scale substances from male wings of both seasonal forms were identified as citral and linalool. The total amount of these substances was four times larger in summer form males than in spring form males.
