Núcleo de Extensão e Pesquisa em Ecologia e Evolução (NEPEE), Departamento de Ciências Biológicas, Universidade do Estado de Minas Gerais, Ituiutaba, MG, Brazil; Pós-graduação em Ecologia e Conservação de Recursos Naturais, Universidade Federal de Uberlândia, MG, Brazil.
Pós-graduação em Ecologia e Conservação de Recursos Naturais, Universidade Federal de Uberlândia, MG, Brazil.
Behav Processes. 2021 Jan;182:104296. doi: 10.1016/j.beproc.2020.104296. Epub 2020 Dec 15.
Trophobiotic interactions occur when phytophagous insects provide a sugary liquid, the honeydew, for ants and obtain defence against predators or parasitoids. The plants may indirectly benefit from an increased ant foraging activity by reducing the herbivorous abundance. These three trophic interactions have been previously studied for several species, but mainly involving plants with extrafloral nectaries, which is a plant structure that also produce attractive substances for ants. Previous studies have reported an ant preference for honeydew over extrafloral nectary content. Therefore, trophobiosis can be an important mediator of ant-plant interactions. In this study, we describe a trophobiotic interaction between Edessa contermina stink bugs and Camponotus blandus ants on the Byrsonima verbascifolia plants occurring in a conservation area of Brazilian savanna. Stink bugs excreted a sugary liquid which was consumed by the ants, and C. blandus ants were observed consuming potential parasitoids. Stink bugs were more abundant in plants containing high food supply and shelter availability. The occurrence of ants depended of the number of inflorescences and trunk circumference of B. verbascifolia. Ant abundance, however, was positively correlated with stink bug abundance and the number of inflorescences. Herbivory was not explained by neither plant architecture nor ant abundance. This high ant activity may benefit plants from a protection against herbivory, but we did not detect this effect during the study period. Hence, the interaction among ants and plants was apparently commensal. We concluded that plant traits were important in ant attraction, but stink bugs foraging also increased ant activity on the plant, but mainly on inflorescences. Therefore, the plant may benefit from an increased defence of inflorescences rather than leaves.
植食性昆虫为蚂蚁提供含糖液体——蜜露，以获得防御捕食者或寄生蜂的能力，从而产生营养共生关系。植物可以通过减少食草动物的数量而间接受益于蚂蚁觅食活动的增加。这三种营养共生关系已经在几种物种中进行了研究，但主要涉及具有额外花蜜的植物，这些植物也会产生对蚂蚁有吸引力的物质。先前的研究报告称，蚂蚁更喜欢蜜露而不是额外花蜜。因此，营养共生可以成为蚂蚁与植物相互作用的重要媒介。在这项研究中，我们描述了巴西热带稀树草原保护区的 Byrsonima verbascifolia 植物上的 Edessa contermina 臭虫和 Camponotus blandus 蚂蚁之间的营养共生关系。臭虫排泄出一种含糖液体，被蚂蚁消耗，并且观察到 C. blandus 蚂蚁消耗潜在的寄生蜂。臭虫在含有高食物供应和遮蔽物的植物中更为丰富。蚂蚁的出现取决于 B. verbascifolia 的花序数量和树干周长。然而，蚂蚁的丰度与臭虫的丰度和花序数量呈正相关。植物结构或蚂蚁丰度都不能解释食草性。尽管蚂蚁活动水平较高，但在研究期间并未发现对植物免受食草性侵害有益的效果。因此，蚂蚁和植物之间的相互作用显然是共生的。我们得出的结论是，植物特征对于蚂蚁的吸引力很重要，但臭虫的觅食也会增加蚂蚁在植物上的活动，尤其是在花序上。因此，植物可能受益于增加对花序的防御，而不是对叶子的防御。
