Local mate competition (LMC) favours female biased clutch sex ratios because it reduces competition between brothers and provides extra mating opportunities for sons. Fig wasps seem to fit LMC model assumptions and lay female-biased sex ratios as predicted. These female biased sex ratios increase fitness greatly. In line with predictions, their sex ratios become less female-biased as the number of mothers laying in the same fig increases. However, this variation results in comparatively small fitness benefits compared to just biased ratios and data suggest substantial mismatches with LMC theory. The mismatches are due to several factors. (1) Multiple foundresses typically lay too many daughters. (2) Single foundress sex ratios are explained by sequential oviposition and ladies-last models. (3) Mortality that typically exceeds 10% may decouple the link between primary sex ratios, the focus of model predictions, and secondary sex ratios of adult wasps that are counted by researchers. (4) Model assumptions are frequently violated: (a) clutch sizes are unequal, (b) oviposition may not be simultaneous (c) cryptic/multiple wasp species inhabit the same host, (d) foundress numbers are systematically undercounted, (e) inbreeding coefficient calculations are inaccurate, and (f) male wasps sometimes disperse. These data and calculations suggest that alternative explanations must be considered seriously. Substantial data show that wasps typically lay most of their male eggs first followed by mostly female eggs require a new approach. These “slope” strategies result in more accurate sex ratios that are automatically adjusted to foundress number, own and relative clutch sizes and to sequential clutches. This effect will alter sex ratios in all species once the egg capacity of a fig is crossed or when interference reduces clutch sizes. In addition to this passive response, the females of about half the studied species have a conditional response that reduces female bias under higher foundress numbers by laying more sons. Therefore, wasps seem to use a very simple strategy that increases their fitness. Natural selection could have optimized parameters of the slope strategy and possibly the existence of the slope strategy itself. Variation in the slope strategy that is the result of natural selection is adaptive. Research should therefore focus on quantifying variables of this slope strategy. Currently, it is unclear how much of the variation is adaptive as opposed to being coincidental by-products.

中文翻译：

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无花果授粉黄蜂对复杂性别比例问题的简单解决方案：综述


本地配偶竞争（LMC）有利于雌性偏向的窝性别比例，因为它减少了兄弟之间的竞争，并为儿子提供了额外的交配机会。无花果黄蜂似乎符合 LMC 模型假设，并且性别比例偏向雌性，正如预测的那样。这些女性偏向的性别比例极大地提高了健康水平。与预测一致的是，随着同一个无花果产下的母亲数量增加，她们的性别比例中女性的偏见会减少。然而，与仅有偏差的比率相比，这种变化导致的适应度收益相对较小，并且数据表明与 LMC 理论存在很大的不匹配。不匹配是由多种因素造成的。 (1) 多名创始人通常会生下太多女儿。 (2) 单母雌性比例可以通过顺序产卵和女士最后模型来解释。 (3) 通常超过 10% 的死亡率可能会使模型预测的重点——主要性别比例与研究人员计算的成年黄蜂的第二性别比例之间的联系脱钩。 (4) 模型假设经常被违反：(a) 窝数不相等，(b) 产卵可能不同时，(c) 隐秘/多种黄蜂物种栖息在同一宿主中，(d) 发现者数量被系统地低估，(e)近交系数计算不准确，并且 (f) 雄性黄蜂有时会分散。这些数据和计算表明必须认真考虑替代解释。大量数据表明，黄蜂通常首先产下大部分雄性卵，然后才产下大部分雌性卵，这需要一种新的方法。这些“倾斜”策略会产生更准确的性别比例，并根据创始人数量、自身和相对离合器尺寸以及顺序离合器自动调整。 一旦无花果的产卵量超过或干扰减少了窝数，这种效应就会改变所有物种的性别比例。除了这种被动反应之外，大约一半的研究物种的雌性还有一种条件反应，即通过产下更多的儿子来减少在较高的创始人数量下的雌性偏见。因此，黄蜂似乎使用了一种非常简单的策略来提高它们的适应性。自然选择可以优化斜坡策略的参数，并且可能优化斜坡策略本身的存在。作为自然选择结果的斜率策略的变化是适应性的。因此，研究应该集中于量化这种斜率策略的变量。目前，尚不清楚有多少变异是适应性的，而不是巧合的副产品。