Deception has evolved in a range of taxa. When deception imposes costs, yet persists over generations, exploited species typically have traits to help them bear or minimise costs. The sexually deceptive orchids, Cryptostylis spp., are pollinated by tricking male haplodiploid wasps (Lissopimpla excelsa) into mating with flowers, which offer no reward and often elicit sperm wastage. We hypothesise that by attracting haplodiploid species, orchids have a pollinator ideally suited to withstand the costs of sexual deception—and a selective advantage compared to other orchids. Haplodiploid females can reproduce with or without sperm—albeit when spermless, females can only have sons. Through orchid deception and sperm wastage, deceived haplodiploid populations could become male biased, providing enough males to share between orchids and females. In this way, pollinator populations can persist despite high densities of sexually deceptive orchids. Here, we aim to broadly test this prediction using museum and digital records of the pollinator, L. excelsa, from sites with or without orchids. For robustness, we also analyse the sex ratio of a sister ichneumonid species that occurs in the same areas but is not deceived by orchids. We found that at sites with orchids, L. excelsa was significantly more male biased than at sites without orchids and significantly more male biased than the sister ichneumonid. This survey is the first to test the population-level effects of sexually deceptive orchids on their pollinator. It supports our prediction that orchid deception can drive male-biased sex ratios in exploited pollinators.

欺骗已经在一系列分类群中发展起来。当欺骗带来成本，但会持续几代人时，被剥削的物种通常具有帮助它们承担或最小化成本的特征。性欺骗性兰花Cryptostylis spp. 是通过欺骗雄性单倍二倍体黄蜂（Lissopimpla excelsa ）授粉的) 与花交配，这不会提供任何奖励，而且经常会导致精子浪费。我们假设，通过吸引单倍二倍体物种，兰花拥有一种非常适合承受性欺骗成本的传粉者，并且与其他兰花相比具有选择性优势。单倍二倍体雌性可以在有或没有精子的情况下繁殖——尽管在没有精子的情况下，雌性只能有儿子。通过兰花欺骗和精子浪费，受骗的单倍二倍体种群可能会偏向男性，从而提供足够的男性在兰花和女性之间共享。通过这种方式，尽管性欺骗性兰花的密度很高，传粉者种群仍然可以持续存在。在这里，我们的目标是使用传粉媒介L. excelsa 的博物馆和数字记录来广泛测试这一预测，来自有或没有兰花的网站。为了稳健性，我们还分析了发生在同一地区但没有被兰花欺骗的姐妹鱼科动物物种的性别比。我们发现，在有兰花的地点，L. excelsa比没有兰花的地点明显更偏向于雄性，并且比姊妹 ichneumonid 更偏向于雄性。这项调查是第一个测试性欺骗兰花对其授粉媒介的人口水平影响的调查。它支持我们的预测，即兰花欺骗可以在被利用的传粉媒介中推动偏向男性的性别比例。