FSD 2010 - Ants

5th International Symposium-Workshop on Frugivores and Seed Dispersal (1985-2010)

Myrmecochory, the dispersal of seeds by ants

Ant-mediated seed dispersal

Myrmecochory occurs in several parts of the world and nearly 3,000 species of plants are known to specifically attract ants as dispersal agents (Wikipedia). This seed dispersal process has evolved independently at least 100 times in angiosperms and is estimated to be present in at least 77 families and 11 000 species, is a key evolutionary innovation and a globally important driver of plant diversity. Ant-mediated seed dispersal provides the best example to date for a consistent effect of any mutualism on large-scale diversification (Lengyel et al. 2009, Source Plos One).

Photo : Rhytidoponera metallica ant holding a seed of Acacia neurophylla by the elaiosome during seed transport (© Benoit Guenard).

Diversity of plants dispersed by ants

"Mediterranean and North American harvester ants (Messor, Atta, Tetramorium, and Pheidole) are essentially destructive, storing and fermenting many seeds and eating them completely. Other ants (Lasius, Myrmica, and Formica species) eat the fleshy, edible appendage (the fat body or elaiosome) of certain specialized seeds, which they disperse. Most myrmecochorous plants (species of violet, primrose, hepatica, cyclamen, anemone, corydalis, Trillium, and bloodroot) belong to the herbaceous spring flora of northern forests. Tree poppy (Dendromecon), however, is found in the dry California chaparral; Melica and Centaurea species in arid Mediterranean regions. The so-called ant epiphytes of the tropics (i.e., species of Hoya, Dischidia, Aeschynanthus, and Myrmecodia—plants that live in “ant gardens” on trees or offer the ants shelter in their own body cavities) constitute a special group of myrmecochores, providing oil in seed hairs, which in ancestral forms must have served in wind dispersal. The primary ant attractant of myrmecochorous seeds is not necessarily oil; instead, an unsaturated, somewhat volatile fatty acid is suspected in some cases. The myrmecochorous plant as a whole may also have specific adaptations; for example, Cyclamen brings fruits and seeds within reach of ants by conspicuous coiling (shortening) of the flower stalk as soon as flowering is over." Source Britannica.

(Photo : a worker of Camponotus cruentatus exploring Helleborus foetidus (Ranunculaceae) seeds in Spain. © Antonio J. Manzaneda)

In a more recent analysis, Lengyel et al. (2009b) found evidence of myrmecochory in 334 genera in 77 families. The number of species in genera in which all or most (450%) species are myrmecochorous is estimated at 11532, distributed in 101 independent origins of myrmecochory in 55 angiosperm families. When all genera in which myrmecochory has been reported are considered, the number of species is 23030, and the minimum number of origins is 147.

Legend: Biogeographical distribution of myrmecochory. The number of evolutionary origins( total n=147) is given for each major biogeographic region (in shades of gray) and more complex distributions (inset). Myrmecochore diversity hotspots are shown in black. Source Lengyel et al. 2009.

Experts of Myrmecochory

(Photo : leaf-cutter Atta sexdens removing the aril of a Copaifera langsdorffii seed © P. Oliveira)

List of the scientists and laboratories working on ants

Please add more - contact : fsd2010(a)yahoo.fr

Books of interest

Gorb E, Gorb S. 2003. Seed dispersal by ants in a deciduous forest ecosystem: mechanisms, strategies, adaptations. Kluwer Academic Publisher.

Rico-Gray V, Oliveira, PS. 2007. The ecology and evolution of ant-plant interactions. The University of Chicago Press.

Myrmecochory on the web

Pictures of ants by Benoit Guenard

With or Without Fruit-Eating Ants - News at FSD2010.org

(Photo : Acromyrmex ants removing fruits of Hyeronima alchorneoides (Euphorbiaceae) in the Brazilian Atlantic Forest. © Marco Aurelio Pizo)

A selection of recent references

Bas JM, et al. 2009. Myrmecochory and short-term seed fate in Rhamnus alaternus: Ant species and seed characteristics. Acta Oecologica 35 : 380-384. Abstract

Beaumont KP, et al. 2009. Combining distances of ballistic and myrmecochorous seed dispersal in Adriana quadripartita (Euphorbiaceae). Acta Oecologica 35: 429-436. Abstract

Boulay R, et al. 2009. Small-scale indirect effects determine the outcome of a tripartite plant-disperser-granivore interaction. Oeocologia 161: 529-537. Abstract

Christianini AV, Oliveira PS, 2009. The relevance of ants as seed rescuers of a primarily bird-dispersed tree in the Neotropical cerrado savanna. Oecologia 160: 735-745. Abstract

Garrido JL, et al. 2009. Influence of elaiosome on postdispersal dynamics of an ant-dispersed plant. Acta Oecologica 35: 393-399. Abstract

Lengyel S, et al. 2009a. Ants sow the seeds of Ggobal diversification in flowering plants. PLoS ONE 4(5): e5480. doi:10.1371/journal.pone.0005480.

Lengyel S, et al. 2009. Convergent evolution of seed dispersal by ants, and phylogeny and biogeography in flowering plants: a global survey. Perspectives in Plant Ecology, Evolution and Systematics. In press, Abstract

Lomov B, et al. 2009. Linking ecological function to species composition in ecological restoration: Seed removal by ants in recreated woodland. Austral Ecology 34: 751-760. Abstract

Manzaneda AJ, et al 2009. Conflicting selection on diaspore traits limits the evolutionary potential of seed dispersal by ants. J. Evol. Biol. 22 : 1407-1417. Abstract

Manzaneda AJ, Rey PJ. 2009. Assessing ecological specialization of an ant–seed dispersal mutualism through a wide geographic range. In press, Ecology.

Ohnishi YK, Suzuki N, 2009. Preferential removal of non-injured seeds by an omnivorous ant, Tetramorium tsushimae Emery, in the seed dispersal of Chamaesyce maculata (L.) small. Ecological Research 24: 1155-1160. Abstract

Peternelli EFO, et al. 2009. Seed transport and removal of the elaiosome of Mabea fistulifera by workers of Atta sexdens rubropilosa (Hymenoptera: Formicidae). Sociobiology 53 : 275-290.