Câmara T, Arnan X, Barbosa V S, Wirth R, Iannuzzi L, Leal I R
Programa de Pós-Graduação em Biologia Vegetal, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, s/n, Cidade Universitária, 50670-901, Recife, PE, Brazil.
CREAF, Cerdanyola de Vallès, Catalunya, Spain.
Bull Entomol Res. 2020 Feb;110(1):77-83. doi: 10.1017/S0007485319000294. Epub 2019 Jun 13.
Flower and leaf herbivory might cause relevant and negative impacts on plant fitness. While flower removal or damage by florivores produces direct negative effects on plant fitness, folivores affect plant fitness by reducing resource allocation to reproduction. In this study, we examine the effects of both flower and leaf herbivory by leaf-cutting ants on the reproductive success of the shrub species Miconia nervosa (Smith) Triana (Family Melastomataceae) in a fragment of Atlantic Forest in Northeast Brazil. We conducted a randomized block-designed field experiment with nine replicates (blocks), in which three plants per block were assigned to one of the three following treatments: undamaged plants (ant exclusion), leaf-damaged plants (ant exclusion from reproductive organs, but not from leaves), and flower + leaf-damaged plants (no exclusion of ants). We then measured flower production, fruit set, and fruit production. Our results showed that flower + leaf-damaged plants reduced flower production nearly twofold in relation to undamaged plants, while flower set in leaf-damaged plants remained constant. The number of flowers that turned into fruits (i.e., fruit set), however, increased by 15% in flower + leaf-damaged plants, while it slightly decreased in leaf-damaged compared to undamaged plants. Contrastingly, fruit production was similar between all treatments. Taken together, our results suggest a prominent role of ant floral herbivory across different stages of the reproductive cycle in M. nervosa, with no consequences on final fruit production. The tolerance of M. nervosa to leaf-cutting ant herbivory might explain its high abundance in human-modified landscapes where leaf-cutting ants are hyper-abundant.
花朵和叶片被食草动物啃食可能会对植物适合度产生相关的负面影响。虽然食花动物去除花朵或对花朵造成损害会对植物适合度产生直接负面影响，但食叶动物通过减少对繁殖的资源分配来影响植物适合度。在本研究中，我们研究了切叶蚁对花朵和叶片的啃食对巴西东北部一片大西洋森林片段中灌木物种神经野牡丹（Smith）Triana（野牡丹科）繁殖成功率的影响。我们进行了一项随机区组设计的田间实验，有九个重复（区组），每个区组中的三株植物被分配到以下三种处理之一：未受损植物（蚂蚁排除）、叶片受损植物（蚂蚁被排除在生殖器官之外，但不排除在叶片之外）和花朵 + 叶片受损植物（不排除蚂蚁）。然后我们测量了花朵产量、坐果率和果实产量。我们的结果表明，与未受损植物相比，花朵 + 叶片受损植物的花朵产量减少了近两倍，而叶片受损植物的坐果率保持不变。然而，在花朵 + 叶片受损植物中，变成果实的花朵数量（即坐果率）增加了15%，而与未受损植物相比，叶片受损植物中的这一数量略有下降。相比之下，所有处理之间的果实产量相似。综合来看，我们的结果表明蚂蚁对花朵的啃食在神经野牡丹生殖周期的不同阶段发挥着重要作用，对最终果实产量没有影响。神经野牡丹对切叶蚁啃食的耐受性可能解释了它在切叶蚁数量超多的人类改造景观中具有高丰度的原因。
