Plant colouration is known to be used by some nocturnal flower-visiting insects to foraging among colourful flowers in dim light. However, it remains unknown whether crepuscular species possibly reliably discriminate plant colouration (i.e. colour and/or brightness) for oviposition even driven by challenges of variably light conditions and similar leaf colouration. Here, we explored this question in the oriental fruit moth Grapholita molesta, a major pest of stone fruits worldwide, using coloured squares under changing illuminants (1000, 100, 1 and 0.01 mW/m²). G. molesta female preferred to oviposit on green and orange over yellow, red, blue and purple with a lower discrimination at starlight (0.01 mW/m²), whereas the preferential brighter white can be discriminated clearly from those achromatic grey and black at all tested light intensities. When both cues were presented in conflicting for oviposition, the moths were more attracted to brightness than colour cues irrespective of light intensity they are exposed to. Interestingly, there was a decrease in the reflectance between young and old leaves of P. persica at similar wavelengths between 500 and 550 nm, providing an apparent brightness. Ovipositing females preferred the brighter light green over the dark green. Our results indicate that as a more reliable cue, brightness of leaves rather than colour plays a more important role for mediating crepuscular moth G. molesta to lay eggs on young leaves in microhabitats in changing light environments. We discuss that the brightness oriented in oviposition task in complex orchards is relevant to leaf apparency.

中文翻译：

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亮度介导产卵蛾（Grapholita molesta）的产卵

已知一些夜间访花昆虫将植物着色用于在昏暗的灯光下在七彩花朵中觅食。然而，即使是在光照条件变化和相似的叶片着色的挑战下，黄昏植物也能否可靠地区分植物的色泽（即颜色和/或亮度），以进行产卵。在这里，我们在不断变化的光源（1000、100、1和0.01 mW / m ²）下使用彩色方块在东方水果蛾Grapholita molesta（世界范围内主要的核果害虫）中探讨了这个问题。G. molesta女性更倾向于在绿色和橙色上排卵，而不是黄色，红色，蓝色和紫色，在星光下的分辨力较低（0.01 mW / m ^2）），而在所有测试光强度下，可以将优先较亮的白色与无色灰色和黑色区分开来。当两个线索都出现产卵冲突时，无论它们受到的光照强度如何，飞蛾比颜色线索更容易吸引亮度。有趣的是，在500至550 nm之间的相似波长下，百日草的新老叶片之间的反射率降低，从而提供了明显的亮度。产卵的雌性比深绿色更喜欢浅绿色。我们的结果表明，作为更可靠的提示，叶片的亮度而不是颜色在介导促蛾蛾G. molesta中起着更重要的作用。在不断变化的光照环境下，在微栖息地的幼叶上产卵。我们讨论了在复杂果园的产卵任务中定向的亮度与叶片的外观有关。