Bee’s are an essential ingredient to a flourishing and diverse world—but so it seems, even they can be replaced.

In the near future we could see farmers outsourcing pollination to autonomous drones! An idea formed by materials chemist Eijiro Miyako of the Japan Advanced Institute of Science and Technology in Nomi—who envisions buble-blowing drones that deliver pollen grains to individual flowers. This tech-savvy solution to the decline in pollinating insects (due to climate change, pesticide use and other factors) is still in development but in the meantime nature has found a resourceful way to mitigate the dwindling presence of their most prolific pollinators.

New research reveals a rare adaption in pollination—where ants have begun performing the role of bee’s. ECU PhD student Nicola Delnevo discovered the trait in a group of shrubs found the Swan Coastal Plain in Western Australia. Delnevo joins BEJournal to discuss the rare occurance of this discovery and its implications for the future of plant pollination.

Photo @DelnevoNicola

Ant Pollination: A Study in Adaption

I’m currently working on a project about the conservation of a threatened plant species, the smokebush Conospermum undulatum. So, what are the first things to understand if we want to save a flowering plant species? First, who are the pollinators, and second, if the movement of pollen within and among populations is still high, because populations are becoming more and more fragmented and isolated because of land clearing, and without pollination there is no future for this plant, as it won’t be able to reproduce. 

So, I started to look at plant-pollinator interactions and I found that ants where active flower visitors. However, ants usually are not effective pollinators because they produce an antimicrobial secretion through their body that kills the pollen.

The primary function of this secretion is very likely antiseptic, with ants spreading it diffusely through their nests to prevent mould growth and infections. But the production of such secretions can be quite expensive from a metabolic point of view, and sometimes can happen that in drier habitats, such as the ones with a Mediterranean-type climate, there is less need for the production of these substances. Thus, I thought that maybe ants in southwest Australia have adapted to the Mediterranean-type environment and are effective pollinators.

What I found, however, is that are not the ants to have adapted, but is the plant that has evolved to use ants as effective pollinators. Conospermum undulatum and other similar species within the same genus, have evolved pollen grains that are resistant to the harmful secretions of ants.

Our study highlights the complexity of ant-flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. 

Another key point is that honeybees have a negative effect on the reproduction of this threatened native plant. This is because honeybees are not native to Australia, but they were introduced for honey production. So, we have native plants that co-evolved for millions of years with native pollinators and developed flowers shaped to facilitate their specific native pollinators.

Our study demonstrated the importance of ant pollination in this threatened species and adds to the ecological roles that ants might play in the region. This highlights the complexity of ant-flower interactions and reinforces the fact that our understanding of these systems is still in its infancy. Our results indicate that such mutualistic associations can happen in unexpected ways, and open the way for future studies to investigate flower-ant interactions in this global biodiversity hotspot.

This is important for wild plants the coevolved for millions of years with their pollinators, but I believe that ant pollination for crops won’t be an option. We must preserve our bees, with a strong emphasis on native bees, which are less known and in some cases are extremely important for the reproduction on wild plants and crops. While honeybees are important pollinators for many species, they can interfere with specialised native insects.