Ants In Your Plants?

Ants are peony-protectors, and the peonies invite them to come. This delightful ants-in-your-plants example reveals one of the many mutually-beneficial, but often hidden, relationships within the web of life all around us. Photo by Becky Nystrom

Do you have peonies in your garden? If so, you’ve likely seen ants crawling or resting on the unopened buds, and perhaps wondered why they are there.

Ants are peony-protectors, and the peonies invite them to come. Young peony buds possess tiny extra-floral nectaries, deliberately and specifically designed only for ants, along the outside edges of the green sepals enclosing each blossom. And so the ants come for the sweet goodies offered! Each microscopic gland subtly oozes a nutritious elixir of sugars, amino acids and water, eagerly consumed by the resident ants, and the ants return the favor by chasing off and protecting the bud from marauding insects and other creatures that may otherwise attack, suck, nibble on, and damage the flower. Once the bloom opens, the ants retreat for a while, but they’ll resume guard duty later on as the plant’s fruit capsules develop. The ants thus defend the peonies’ flowers, fruits and seeds, and the peonies, in turn, nourish their amazing little allies with yummy and valuable nutrient rewards.

So what if you’d like an ant-free bouquet of those beautiful buds and blooms for your kitchen table? Just cut the flower stems, gently shake off the ants in place, put the peonies in a vase of water and leave them outside for about 30 minutes — any additional ants not already shaken off will soon abandon their flower. Never, ever use pesticides on these little helpers. Although we humans are often unaware of the good deeds they do, according to SUNY ESF and Cornell University entomologist and master gardener, Roberta Gibson (blog.wildaboutants.com), ants are known to help protect over 70 different flower families in the U.S., ranging from buttercups and violets to sunflowers, vetch and even some cacti — all of which provide a variety of extra-floral nectaries for attracting and rewarding their ant defenders. It is also known that the biological health of woodlands is significantly aided by certain foraging ant species which consume or deter herbivores and seed predators such as stinkbugs, leaf-mining beetles, sawfly and various caterpillars in spruce, pine, larch, beech, birch and oak. The trees, in turn, provide shelter, nectar and other rewards to maintain the ants within their foliage, trunk, and roots.

Ecologically, ants play many other beneficial roles as well, serving as teeny tillers of the soil, nutrient mobilizers, diminutive pollinators, and perhaps most impressively, dispersers of seeds and spores. In fact, between 11,000 and 23,000 species of plants around the world are known to specifically attract ants as their dispersal agents. As such these little creatures play big roles affecting where countless seeds and spores sprout, and on the larger ecological scale, they impact plant reproduction and survival, species richness and community structure. Amazingly, in the woodlands and wetlands of our Chautauqua region and throughout most of eastern North America, foraging ants are responsible for dispersing the seeds of more than 30% of our lovely spring ephemerals and garden favorites, including hepatica, violets, wild ginger, trailing arbutus, trillium, trout lily, Dutchman’s breeches, bloodroot, bleeding heart, milkwort, primrose, cyclamen, anemone, twinleaf and even the spores of bracken and polypody ferns!

This fascinating mutualistic ant-plant relationship is called “myrmecochory” and involves the plant’s offering of a fatty food body, or “elaiosome” tightly attached to the flower seed or fern spore. In the case of our spring ephemerals, worker ants eagerly gather the seeds and bring them home to their underground tunnels, where the nutrient-rich elaiosomes are removed and fed to their larvae. Remaining intact and containing a tiny embryonic wildflower within, each left-over seed is discarded in a special underground chamber containing the ant society’s compost pile and within this well-aerated waste-heap. The young seedlings experience a perfectly-protective, favorable and fertile place in which to germinate. This is especially critical to our native spring wildflowers since, in temperate forests such as ours, seed-eating rodents and other predators remove approximately 60 percent of all seeds within just a few days of release and eventually take nearly all of those not carried off and hidden by the ants.

Ants serve as dispersers, planters, and defenders of many botanicals, and they play a significant role in the flow of life in the forests, fields, and gardens of our watersheds.

Their societies are ancient, diverse, and complex, and they deserve our respect. Within the woodlands of the Chautauqua region, and elsewhere, ants and wildflowers are intimately woven together within nature’s tapestry, supporting one another’s reproductive success and survival and contributing to the health and stability of our natural world.

Becky Nystrom is a Professor of Biology at Jamestown Community College, a founding trustee and current board director of the CWC and a longtime CWC supporter and volunteer. The Chautauqua Watershed Conservancy is a local not-for-profit organization dedicated to preserving and enhancing the water quality, scenic beauty and ecological health of the lakes, streams, wetlands and watersheds of the Chautauqua region.

For more information, call 664-2166 or visit chautauquawatershed.org or facebook.com/ chautauquawatershed.

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