Delisle Johanne, Bouchard André
Canadian Forest Service-Quebec Region, Natural Resources Canada, 1055 du P.E.P.S., P.O. Box 3800, G1V 4C7, Sainte-Foy, QC, Canada.
Oecologia. 1995 Dec;104(4):508-517. doi: 10.1007/BF00341349.
This study examines how Choristoneura rosaceana male quality, as determined by larval diet, age and mating history, affects the reproductive success of both sexes. While the size of the spermatophore produced at first mating increased linearly with male age, the frequency of mating was significantly higher for middle-aged males (2-4 days old) than younger (0-2 days old) or older (6-8 days old) individuals, when both sexes were fed on artificial diet. However, the duration of copulation was longer in couples with older than younger males. The observed age-related changes in spermatophore size had no significant effect on female longevity, fecundity or fertility, suggesting no direct relationship between male investment and spermatophore size under these experimental conditions. Different larval food sources (artificial diet, maple and hazelnut) did not affect the proportion of 2-day-old virgin males that mated; however, the proportion that remated was significantly higher for males reared on high-quality food (maple and artificial diet) than those on hazelnut, a poorer food source. There was a 5-fold decline in spermatophore size between the first and second matings on all diets, but female reproductive output was reduced by only 25%. In contrast, while the first spermatophore produced by males on hazelnut was 1.5 times smaller than those produced on maple and artificial diet, the fecundity of their mates was 40% less than those mated with high-quality virgin males. These results provide additional support to the idea that spermatophore size is not a valuable indicator of male quality. Most tethered females placed in the field during the first flight period mated with virgin males (based on the size of the spermatophore), suggesting that female choice exists in this species. These results are discussed in relation to the incidence of polyandry in naturally occurring populations of Choristoneura and the potential use of size and/or chemical cues by females to assess male quality.
本研究考察了由幼虫饮食、年龄和交配史所决定的蔷薇卷叶蛾雄蛾质量如何影响两性的繁殖成功率。虽然首次交配时产生的精包大小随雄蛾年龄呈线性增加，但当两性都以人工饲料喂养时，中年雄蛾（2 - 4日龄）的交配频率显著高于年轻雄蛾（0 - 2日龄）或老年雄蛾（6 - 8日龄）。然而，与年轻雄蛾配对的雌蛾相比，与老年雄蛾配对的雌蛾交配持续时间更长。观察到的精包大小与年龄相关的变化对雌蛾的寿命、繁殖力或生育力没有显著影响，这表明在这些实验条件下，雄蛾投资与精包大小之间没有直接关系。不同的幼虫食物来源（人工饲料、枫树和榛子）并不影响2日龄未交配雄蛾的交配比例；然而，以优质食物（枫树和人工饲料）饲养的雄蛾再次交配的比例显著高于以较差食物来源榛子饲养的雄蛾。在所有饲料条件下，第一次和第二次交配之间精包大小下降了5倍，但雌蛾的繁殖产出仅减少了25%。相比之下，虽然雄蛾在榛子上产生的第一个精包比在枫树和人工饲料上产生的精包小1.5倍，但其配偶的繁殖力比与优质未交配雄蛾交配的雌蛾低40%。这些结果为精包大小不是雄蛾质量的重要指标这一观点提供了更多支持。在首次飞行期放置在野外的大多数被拴系的雌蛾与未交配雄蛾交配（根据精包大小判断），这表明该物种存在雌性选择。本文结合蔷薇卷叶蛾自然种群中多配偶制的发生率以及雌性利用大小和/或化学信号评估雄蛾质量的潜在用途对这些结果进行了讨论。
