Despite being frequent visitors of flowers where pollen may attach to their bodies, the lack of evidence supporting ant-pollination and a number of physical and chemical limitations has led to the belief that ants play limited or negligible roles as pollinators.
However, several studies have shown how some plant species are primarily pollinated by ants and that they, contrary to popular belief, are in some cases just as effective as bees.
So no matter the scarcity of evidence or the different factors which affect their proficiency, ants are in fact pollinators.
In this article we’ll look further into ants as pollinators as we discuss their relationship with flowers. We’ll look into several studies as well as the reasons why ants are considered to be relatively ineffective at the role.
But before that, let’s talk about pollinators.
What Are Pollinators?
Pollinators or pollination vectors are animals which help transfer pollen from male to female flowers which in turn enables fertilization that leads to the production of seed and fruit. These animals include birds, bats, and insects like butterflies.
Ants As Pollinators
While ants are mostly known as foragers, they also indulge in sap or nectar produced by plants. As such, some ants frequently visit plants and flowers for food like other insects. This again, allows pollen to attach to their bodies which may then be transferred to other flowers. Hence, the reason ants may be considered pollinators.
For instance, research has shown that the small, self-incompatible, annual plant Polygonum cascadence is regularly pollinated by the ant species Formica argentea.
Another study on the relationship between ants and the plant Conospermum undulatum, also shows ants to be as effective pollinators and on par with bees in terms of germination rate after contact.
In general, ant-pollination occurs with low-growing, self-compatible plants that do not require long-distance pollen dispersal.
Why Are Ants Ineffective Pollinators?
Despite these studies however, ants are still generally seen to be ineffective pollinators due to a number of factors. It is due to these factors that ant-pollination is said to rely on quantity, that is the number of visits, to compensate for the lack of quality. These factors are as follows:
- Size: Compared to other pollinators, ants are small insects. Because of this, the amount of pollen grains that may attach to their bodies are relatively limited. That is, if pollen even gets to attach to their bodies at all. Due to their small size, it’s also possible for them to avoid contact with anthers and stigmas while getting nectar, thus preventing them from becoming vectors in the first place.
- Smooth Bodies: Also, unlike other pollinators that are generally hairy, most ant species tend to have relatively smooth bodies. This makes it more difficult for pollen to attach to their bodies and thus further reduces their efficiency as pollinators.
- Mandibles: Ant mouthparts aren’t the best for pollination. Instead of proboscis or long elongated sucking mouthparts suitable for reaching nectar, ants have mandibles which they use for biting or cutting down food. Due to the nature of these mouthparts, they may end up damaging the reproductive organs of plants.
- Wingless: While some ants may grow wings, worker ants which forage and visit flowers do not. This means that they have to crawl to reach nectar, which while for the most part isn’t a problem due to their speed, does make them inefficient pollen vectors when compared to those capable of flight. This also makes it more likely for ants to take nectar without effectively cross-pollinating flowers.
- Behavior: Ants also tend to visit the same plant over and over, which thus further reduces their effectiveness when it comes to cross-pollination. This is one reason why ant-pollination typically occurs with self-compatible plants.
- Chemical Secretion: Ants secrete chemical antibiotics to defend and prevent infections caused by pathogenic organisms. The same secretions however, disrupt pollen function by killing the pollen grains that come into contact with ants.
- Plant Defenses: Plants have developed defense mechanisms to prevent predators from damaging their reproductive organs. One such defense mechanism is the use of extrafloral nectaries or specialized nectar-secreting glands outside of flowers. This prevents ants from having to go to flowers for nectar, effectively reducing the chance of damage. However, this also reduces the opportunity for pollination.
- Relationship With Other Pollinators: Ants don’t have the best relationship with other pollinators. They’re known to attack and harass them, thus leading to decreased floral visitation from more efficient vectors. In fact, research has shown that bumblebees avoid flowers with ant scent. So while this particular reason doesn’t pertain to the ability of ants as pollinators per se, it does show how they may negatively affect pollination.
Are Ants Bad For Plants?
Not necessarily. Ants don’t tend to directly harm plants and they do in fact provide a number of benefits. However, as mentioned earlier, they may end up damaging the reproductive organs of plants due to their mandibles which aren’t necessarily the best for collecting nectar. Aside from that, they may also foster the growth of pests like aphids which directly feed on plants.
Do Ants Eat Flowers?
No, ants don’t eat flowers. Instead, they visit flowers for nectar, a food source which contains sugars, amino acids, lipids, and other organic compounds.
Do Ants Eat Grass?
Likewise, ants also don’t eat grass. Some species however, do eat grass seeds. They’re also not safe from leaf cutter ants which break and gather leaves to cultivate fungus which they eat.
Despite a number of factors which affect their efficiency and effectiveness, ants remain to be pollinators as highlighted by the studies presented. That’s not to say however, that these
factors have no bearing. It is due to these factors that ant-pollination is considered rare, as they are pretty much limited as vectors to select plant species. So all in all, it is indeed true that ants are relatively ineffective when it comes to other pollinators such as bees. Yet again, just because they’re worse doesn’t mean they can’t do the job.