Tallamy Douglas W, Darlington Mark Burton, Pesek John D, Powell Bradford E
Department of Entomology and Applied Ecology, College of Agriculture and Natural Resources, Delaware Agricultural Experiment Station, University of Delaware, Newark, DE 19717-1303, USA.
Proc Biol Sci. 2003 Jan 7;270(1510):77-82. doi: 10.1098/rspb.2002.2198.
In the spotted cucumber beetle, Diabrotica undecimpunctata howardi (Coleoptera: Chrysomelidae), males court females during copulation by stroking them with their antennae. Stroking occurs exclusively during the first stages of copulation, after a male has penetrated a female's vaginal duct but before he is allowed access to her bursa copulatrix. Females accept the spermatophore of fast-stroking males and reject those of slow-stroking males by relaxing or constricting muscles distorting the vaginal duct. Here, we measure the repeatability of stroking behaviour within males, examine the effect of losing one antenna on male attractiveness and test whether such female control results in direct phenotypic benefits for the discriminating female or indirect genetic benefits that appear in her offspring. We also use a half-sibling design to quantify the variance and heritability of stroking speed and endurance. Female beetles were paired with a male that was known to stroke either quickly or slowly. No difference was found in the resulting fecundity or egg-hatching rate of the females, or in the survivorship, development rate, size, age at first reproduction or fecundity of their offspring indicating that no direct benefits are gained by discriminating among males on the basis of stroking speed. There were, however, good-genes benefits for the mates of fast-stroking males. Offspring of fast-stroking fathers were also fast strokers and were more likely to be accepted as mates than offspring of slow-stroking fathers. There was substantial variance among sires in stroking speed and endurance and the heritability of each trait was high. The antennal stroking rate was highly repeatable in successive mating attempts and males with only one antenna were not accepted as mates. The repeatability within males, variability between males and heritability between generations of copulatory stroking combine to provide females with a reliable and honest signal of the genetic quality of courting males.
在斑纹黄瓜甲虫——十一星黄瓜甲虫（Diabrotica undecimpunctata howardi，鞘翅目：叶甲科）中，雄性在交配时会用触角抚摸雌性来求爱。抚摸行为仅发生在交配的最初阶段，即雄性插入雌性阴道管之后，但在进入其交配囊之前。雌性通过放松或收缩使阴道管变形的肌肉，接受快速抚摸雄性的精包而拒绝慢速抚摸雄性的精包。在此，我们测量了雄性体内抚摸行为的重复性，研究失去一只触角对雄性吸引力的影响，并测试这种雌性控制是否会为有辨别力的雌性带来直接的表型益处，或者为其后代带来间接的遗传益处。我们还采用半同胞设计来量化抚摸速度和耐力的方差及遗传力。将雌性甲虫与已知抚摸速度快或慢的雄性配对。结果发现，雌性的产卵量或卵孵化率，以及其后代的存活率、发育速度、大小、首次繁殖年龄或产卵量均无差异，这表明基于抚摸速度对雄性进行辨别并不会带来直接益处。然而，与快速抚摸雄性交配的雌性会获得优质基因的益处。快速抚摸雄性的后代也是快速抚摸者，并且比慢速抚摸雄性的后代更有可能被接受为配偶。在父亲之间，抚摸速度和耐力存在很大差异，且每个性状的遗传力都很高。在连续的交配尝试中，触角抚摸率具有高度重复性，只有一只触角的雄性不被接受为配偶。雄性体内的重复性、雄性之间的变异性以及交配抚摸行为在代际间的遗传力共同为雌性提供了求偶雄性遗传质量的可靠且真实的信号。
