Nectar robbers are animals that extract nectar through holes made in floral tissues. This behaviour has a wide spectrum of consequences for the plant that range from negative, to neutral, to positive according to life history traits of the interacting organisms and the ecological mechanisms involved. Lonicera etrusca has long tubular flowers producing large quantities of nectar and undergoing high levels of nectar robbing. Despite this, robbing seems to have neutral effects on the reproduction of the species. The aim of this work is to understand why this pollinator‐dependent plant is not affected by an interaction that is commonly detrimental for plants. To achieve this goal we try to answer two questions: 1) do nectar robbers deposit suitable pollen for plant reproduction after a visit? And, 2) is the visitation rate of legitimate visitors affected by nectar robbing? We experimentally studied the details of the reproductive compatibility system of the plant and compared pollen tube growth after single visits of the main nectar robbers. We made observations on plants of three populations to study the effect of robbers on the visitation rates of legitimate foragers. The results revealed that nectar robbers effectively perform cross‐pollination. Visitation rates of legitimate visitors are reduced by nectar robbing. The net neutral effect observed for L. etrusca is the result of two processes: on one side the direct positive effect of nectar robbers acting as pollinators, and on the other, a negative indirect effect caused by the decrease in visitation rates of legitimate visitors. Since the number of ovules in this species is low, both legitimate visitors and robbers contribute to an efficient cross‐pollination. This example illustrates how neutral effects for the plant can arise as the final result of a complex interaction between plants, legitimate visitors and robbers.

中文翻译：

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花蜜抢劫和植物繁殖：正面和负面影响的相互作用

花蜜强盗是通过花组织中的孔提取花蜜的动物。根据相互作用生物的生命历史特征和所涉及的生态机制，这种行为对植物具有广泛的后果，范围从负面，中性到正面。忍冬有长的管状花，产生大量的花蜜，并经历高水平的花蜜抢劫。尽管如此，抢劫似乎对物种的繁殖具有中性影响。这项工作的目的是了解为什么这种依赖传粉媒介的植物不会受到通常对植物有害的相互作用的影响。为了实现这一目标，我们尝试回答两个问题：1）花蜜强盗是否在探视后存放了适合植物繁殖的花粉？而且，2）合法游客的访问率是否受到花蜜抢劫的影响？我们通过实验研究了植物的生殖相容性系统的细节，并比较了主要花蜜强盗的单次造访后花粉管的生长。我们对三个种群的植物进行了观察，以研究强盗对合法觅食者探望率的影响。结果表明，花蜜强盗有效地进行了异花授粉。蜜汁抢劫会降低合法游客的探访率。观察到的净中性效应L. etrusca是两个过程的结果：一方面，花蜜强盗扮演传粉者的直接积极作用，另一方面，由于合法访客的访问率降低而引起的负面间接影响。由于该物种的胚珠数量很少，因此合法的访客和强盗都有助于有效的异花授粉。这个例子说明了植物，合法访客和强盗之间复杂互动的最终结果是如何对植物产生中性影响。