Female mate preference for egg-caring males in the giant water bug Diplonychus rusticus (Heteroptera Belostomatidae)

Paternal care can be maintained under sexual selection in case that it helps caring males to attract more mates. Females of two back-brooding water bug species, the belostomatids Appasus major and A. japonicus, prefer egg-caring males over non-caring males. Here, we tested under laboratory and field conditions whether females of another belostomatid species, Diplonychus rusticus, prefer egg-caring males as mating partners. Caring males received more eggs from females than non-caring males under the both conditions. Our results suggest that sexual selection plays an important role in maintaining paternal care not only in species of the genus Appasus, but also in the genus Diplonychus.

父育行为（Paternal care）可在性选择作用下得以维持，若其能够帮助携卵雄性吸引更多配偶。两种背负育幼型负子蝽科（Belostomatidae）昆虫——巨负子蝽（Appasus major）与日本负子蝽（A. japonicus）的雌性个体，均偏好携卵雄性而非未携卵雄性。本研究在实验室与野外环境下，检验了另一负子蝽科物种锈色异负子蝽（Diplonychus rusticus）的雌性是否会将携卵雄性作为优选交配对象。在两种实验条件下，携卵雄性均能从雌性处获得更多卵块。本研究结果表明，性选择不仅在负子蝽属（Appasus）物种的父育行为维持中发挥重要作用，在异负子蝽属（Diplonychus）物种中亦是如此。