Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
Faculty of Arts, Science and Technology, University of Northampton, Waterside Campus, Northampton, NN1 5PH, UK.
Am J Bot. 2020 Oct;107(10):1355-1365. doi: 10.1002/ajb2.1545. Epub 2020 Oct 24.
Species of Apocynaceae are pollinated by a diverse assemblage of animals. Here we report the first record of specialized cockroach pollination in the family, involving an endangered climbing vine species, Vincetoxicum hainanense in China. Experiments were designed to provide direct proof of cockroach pollination and compare the effectiveness of other flower visitors.
We investigated the reproductive biology, pollination ecology, pollinaria removal, pollinia insertion, and fruit set following single visits by the most common insects. In addition, we reviewed reports of cockroaches as pollinators of other plants and analyzed the known pollination systems in Vincetoxicum in a phylogenetic context.
The small, pale green flowers of V. hainanense opened during the night. The flowers were not autogamous, but were self-compatible. Flower visitors included beetles, flies, ants and bush crickets, but the most effective pollinator was the cockroach Blattella bisignata, the only visitor that carried pollen between plants. Less frequent and effective pollinators are ants and Carabidae. Plants in this genus are predominantly pollinated by flies, moths and wasps.
Globally, only 11 plant species are known to be cockroach-pollinated. Because their range of floral features encompass similarities and differences, defining a "cockroach pollination syndrome" is difficult. One commonality is that flowers are often visited by insects other than cockroaches, such as beetles, that vary in their significance as pollinators. Cockroach pollination is undoubtedly more widespread than previously thought and requires further attention.
夹竹桃科的物种由多种动物组成的集合授粉。在这里，我们报告了该科中蟑螂授粉的第一个记录，涉及中国濒危攀援藤本植物海杧果。实验旨在提供蟑螂授粉的直接证据，并比较其他访花者的有效性。
我们调查了最常见昆虫单次访问后的生殖生物学、传粉生态学、花粉移除、花粉插入和果实结实情况。此外，我们回顾了蟑螂作为其他植物传粉者的报道，并在系统发育背景下分析了海杧果中已知的传粉系统。
海杧果的小而淡绿色花朵在夜间开放。这些花不自交，但自交亲和。花访客包括甲虫、苍蝇、蚂蚁和蟋蟀，但最有效的传粉者是蟑螂扁头蜚蠊，它是唯一在植物间携带花粉的访客。较少出现且效率较低的传粉者是蚂蚁和步甲科。该属植物主要由蝇类、蛾类和蜂类授粉。
全球已知只有 11 种植物是由蟑螂授粉的。由于它们的花部特征范围涵盖了相似性和差异性，因此很难定义“蟑螂授粉综合征”。一个共同点是，花朵经常被蟑螂以外的昆虫访问，例如在传粉者中的重要性不同的甲虫。蟑螂授粉无疑比以前认为的更为广泛，需要进一步关注。
