Wing coloration and courtship behaviour of the damselfly Calopteryx japonica

日本豆娘属的Calopteryx japonica在它们的翅膀上有两种颜色多态性。未成熟和成熟的雌鸟的翅膀都是棕灰色的。未成熟雄性的翅膀也有雌性色素，但成熟雄性的翅膀有明亮的蓝绿色，雄性色素，由于彩虹色的翅膀静脉。我们发现，在它们的领地内，成年雄性会攻击其他成年雄性，但不会攻击雌性和未成熟的雄性，这表明雄性在视觉上区分了雄性色素的颜色。在选择实验中，我们向领地雄性提供了四种不同的束缚模式。领地雄性攻击成熟雄性模型，并对成熟雌性模型表现出繁殖行为。用灰色喷雾覆盖成熟雄性模型的翅膀会导致领地雄性的攻击行为完全消失。另一方面，翅膀上覆盖着明亮的蓝绿色颗粒的雌性模型，模仿成熟的雄性，受到有领地意识的雄性的攻击。结果表明，日本锦翅明亮的蓝绿色在雄性领地行为中起着重要作用。

Damselflies of the genus Calopteryx japonica feature two types of colour polymorphism in their wings. The wings of both immature and mature females have a brown-greyish, gynochrome colour. The wings of the immature male also have the gynochrome colour, but the mature male wings have a bright blue-green, androchrome colour, due to iridescent wing veins. We found that the adult males in their territory attack other mature males, but not females and immature males, suggesting that males visually distinguish the androchrome colour. In choice experiments, we presented four different tethered models to territorial males. The territorial male attacked the mature male model, and showed reproductive behaviour display towards the mature female model. Covering the wings of a mature male model with grey spray resulted in a complete disappearance of the aggressive behaviour of the territorial males. On the other hand, female models with wings covered by bright blue-green particles, thus mimicking a mature male, were attacked by territorial males. The results indicate that the bright blue-green iridescence of the wings of C. japonica males plays a significant role in male territorial behaviour.