Gómez J M, Zamora R
Dpto. Biología Animal y Ecología, Facultad de Ciencias, Universidad de Granada, 18001, Granada, Spain.
Oecologia. 1992 Sep;91(3):410-418. doi: 10.1007/BF00317631.
We have analysed the importance of worker ants (Proformica longiseta, Formicidae) as pollinators of a mass-flowering woody plant (Hormathophylla spinosa, Cruciferae) in the high-mountain area of the Sierra Nevada (southern Spain). We have quantified the abundance and foraging behavior of P. longiseta in comparison with winged flower visitors. We have also examined, by means of selective exclusion experiments, the role of ants as true pollinators, comparing them with the winged flower visitors. A total of 39 species belonging to 18 families visited the flowers of H. spinosa. All the visitors were winged insects, except P. longiseta, a species which alone made up more than 80% of the total number of insects found on the flowers. All pollinators of H. spinosa had similar foraging patterns, with 98% of total movements made between flowers within the same plant. Ants always made contact with the plant reproductive organs when foraging for nectar, and transferred large numbers of pollen grains. However, pollen exposed to ants for brief periods exhibited reduced percentage of germination. P. longiseta is both the most abundant and spatio-temporally predictable flower visitor of H. spinosa. These characteristics, weighted by their flower visitation rate, make worker ants the pollinator that maintains the strongest mutualistic interaction with H. spinosa. The exclusion experiments show that workers behave as true pollinators, since they contribute to increase the number of viable seeds produced by H. spinosa. The key factor of this interaction is mainly the great density of workers throughout the flowering period. In short, the H. spinosa-P. longiseta mutualistic interaction mainly depends on its high probability of occurrence.
我们分析了工蚁（长刺原蚁，蚁科）作为内华达山脉（西班牙南部）高山区一种大量开花木本植物（刺叶芹，十字花科）传粉者的重要性。我们量化了长刺原蚁与有翅访花者相比的丰度和觅食行为。我们还通过选择性排除实验，研究了蚂蚁作为真正传粉者的作用，并将它们与有翅访花者进行比较。共有18个科的39种昆虫访问了刺叶芹的花朵。除了长刺原蚁外，所有访花者都是有翅昆虫，长刺原蚁这一物种单独就占了花朵上发现的昆虫总数的80%以上。刺叶芹的所有传粉者都有相似的觅食模式，98%的总移动发生在同一植株的花朵之间。蚂蚁在觅食花蜜时总是会接触到植物的生殖器官，并转移大量花粉粒。然而，短时间接触蚂蚁的花粉发芽率降低。长刺原蚁是刺叶芹最丰富且时空分布可预测的访花者。这些特征，再加上它们的访花率，使工蚁成为与刺叶芹保持最强互利共生关系的传粉者。排除实验表明，工蚁起到了真正传粉者的作用，因为它们有助于增加刺叶芹产生的 viable 种子数量。这种相互作用的关键因素主要是整个花期工蚁的高密度。简而言之，刺叶芹 - 长刺原蚁的互利共生关系主要取决于其高发生概率。
