Ng Swit Yee, Bhardwaj Shivam, Monteiro Antónia
Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.
Yale-NUS College, 10 College Avenue West, Singapore 138609, Singapore, Singapore.
J Insect Sci. 2017 Jul 1;17(4). doi: 10.1093/jisesa/iex053.
Male investment towards reproduction is substantial in some species, and this leads to the evolution of choosy males. Male choice is often directed towards female phenotypes that are good indicators of fecundity such as body size, age, or virgin status, and often acts in the same direction as fecundity selection. In insects, only a few examples exist where male choice is directed towards female ornaments as proxies Butler of female quality. Here, we use dry season males of the sex-role reversed butterfly species Bicyclus anynana to test for differences in male choosiness and investment towards females of varying attractiveness using ornament-manipulations. Male reproductive investment in this species is in the form of a nuptial gift, a spermatophore, given to females upon mating. Males were placed in cages with either wild-type ornamented females or with nonornamented females (center of the dorsal forewing eyespots painted over), and time to mating, duration of mating, and longevity of males and females after a single mating were measured. Ornament manipulations consisted of blocking the UV-reflective scales in the center of the dorsal forewing eyespots of females, a known sexual ornament. Males displayed lower latency to mate and longer mating durations with ornamented females. The longer mating duration did not, however, translate in the transfer of a nuptial gift that increased female longevity or reduced male longevity. Instead, we propose that longer mating durations with ornamented females may represent increased mate guarding behavior or increased sperm transfer.
在某些物种中,雄性对繁殖的投入很大,这导致了挑剔雄性的进化。雄性选择通常针对那些能很好地指示繁殖力的雌性表型,如体型、年龄或处女状态,并且通常与繁殖力选择的方向一致。在昆虫中,只有少数例子表明雄性选择针对雌性的装饰,将其作为雌性品质的代表。在这里,我们使用性别角色反转的蝴蝶物种鞍带环蝶的旱季雄性个体,通过对装饰进行操作,来测试雄性在对不同吸引力的雌性的挑剔程度和投入方面的差异。在这个物种中,雄性的生殖投入是以交配礼物的形式,即一个精包,在交配时给予雌性。将雄性放置在笼子里,笼子里要么是具有野生型装饰的雌性,要么是没有装饰的雌性(前翅背眼斑中心被涂盖),并测量交配时间、交配持续时间以及单次交配后雄性和雌性的寿命。装饰操作包括遮挡雌性前翅背眼斑中心的紫外线反射鳞片,这是一种已知的性装饰。雄性与有装饰的雌性交配时,交配潜伏期较短,交配持续时间较长。然而,较长的交配持续时间并没有转化为能增加雌性寿命或降低雄性寿命的交配礼物的传递。相反,我们认为与有装饰的雌性较长的交配持续时间可能代表着增加的配偶守卫行为或增加的精子传递。