Huq Manizah, Bhardwaj Shivam, Monteiro Antónia
Department of Biological Sciences, National University of Singapore, Singapore.
Science Division, Yale-NUS College, Singapore.
J Insect Sci. 2019 Jan 1;19(1). doi: 10.1093/jisesa/iez014.
Butterflies often use their dorsal and ventral wing color patterns for distinct signaling functions. Color patterns on hidden dorsal wing surfaces are often used in sexual signaling, while exposed ventral patterns are often used to ward off predator attacks. At rest, however, part of the ventral forewings are often hidden by the hindwings, allowing individuals to also use the patterns on this wing surface for sexual signaling. Here, we test this hypothesis in Bicyclus anynana (Butler, Lepidoptera, Nymphalidae) butterflies by first determining the degree of sexual dimorphism in ventral forewing patterns, focusing on the eyespots, from both wet and dry season forms, and then testing the role of the larger ventral forewing eyespots of dry season females in male mate choice. We also test male investment in reproduction. We show that ventral forewing UV-reflective eyespot centers, in addition to dorsal forewing eyespot centers previously examined in this species, play a role in sexual signaling as males preferentially mated with females with their ventral eyespot centers intact instead of blocked with black paint. This male preference, however, did not translate into a detectable higher reproductive investment via a single mating toward ornamented females. This study provides an example of how ventral forewing patterns, often hidden by hindwings, are used in sexual communication, in this case by females to attract males.
蝴蝶常常利用其翅膀背腹面的颜色图案来实现不同的信号功能。隐藏在翅膀背面的颜色图案通常用于性信号传递，而暴露在外的腹面图案则常被用于抵御捕食者的攻击。然而，在休息时，部分腹面前翅常常被后翅遮挡，这使得个体也能够利用这一翅面的图案进行性信号传递。在此，我们以枯叶蛱蝶（巴特勒，鳞翅目，蛱蝶科）为研究对象来验证这一假设，首先确定腹面前翅图案（重点是眼斑）在雨季型和旱季型中的性二态性程度，然后测试旱季型雌性较大的腹面前翅眼斑在雄性配偶选择中的作用。我们还测试了雄性在繁殖方面的投入。我们发现，除了此前在该物种中研究过的背面前翅眼斑中心外，腹面前翅紫外线反射眼斑中心也在性信号传递中发挥作用，因为雄性更倾向于与腹面眼斑中心完好而非被黑漆遮挡的雌性交配。然而，这种雄性偏好并未转化为通过单次交配对具有装饰性的雌性进行可检测到的更高繁殖投入。这项研究提供了一个例子，说明通常被后翅遮挡的腹面前翅图案是如何在性交流中被利用的，在这种情况下是雌性利用其来吸引雄性。
