Nature on our doorsteps: Springtime flowers and ants – a beneficial relationship
Rosaleen Dwyer is the County Heritage Officer at South Dublin County Council – every week she gives us an insight into nature on our doorsteps and the beautiful biodiversity of its plants and wildlife.
PRIMROSES and Violets begin to flower as early as February, especially in sheltered sunny locations along the edges of woodlands, hedgerows, or on grassy banks by the side of the road.
These early springtime flowers offer valuable food to insects that are just emerging from their winter sleep.
With Primroses and Violets however, it is not just pollen and nectar that they offer.
Their seeds are also of interest, but not in the way that might generally be assumed.
Ants are attracted to Primrose and Violet seeds.
They are not interested in the seeds themselves though, but they are drawn to a little fleshy packet of rich fat that is attached to one end of the seed.
This little packet of food is called an elaiosome, from the Greek words for ‘elaion’ meaning oil or fat, and
‘soma’ meaning body.
Studies suggest that the fatty elaiosomes emit a chemical scent that attracts the ants to the flowers.
It is thought that this chemical causes the ant to think that the seed is a dead ant.
Sunny yellow primroses brighten roadside banks and hedgerows in springtime
Some ant species carry their dead back to their nest, so the ants are motivated to collect the seeds and carry them home.
Once inside the nest, the ants remove the nutrient-rich elaiosomes and feed them to their rapidly growing larvae.
The ants have no interest in the seeds, so they dispose of them on their waste heap inside their nest.
This heap is composed of ant frass (ant poop) and any other waste, like dead ants or larvae.
This waste forms a nice rich pile of fertiliser in which the discarded flower seeds can safely germinate and grow, away from other nibbling insects.
In this special relationship between the plants and the ants, both partners benefit.
The ants get a valuable source of food in the form of a nutrient-rich lump of fat, and the plant benefits as the ants carry its seeds away from the parent plant to grow elsewhere in the vicinity.
