Other Pollinators — Ants
People often ask, "Do ants pollinate?"
Ants are seen visiting flowers with great frequency. Are ants capable of
pollinating flowers? Do they have what it takes to carry pollen from one flower to another, preferably of another
plant?
While ants are among the most abundant, diverse and ecologically important groups of insects, on the whole they
are not good pollinators. A few succulents and other plants are pollinated by ants. Plants in harsh, drylands seem
to rely on ants, as there might be few other pollinators available. Ant-pollinated succulent plants also tend to grow
close to the ground where ants can more easily access the flowers
Why don’t ants make good pollinators? Most pollinators can fly from plant to plant. Ants, lacking wings, they
typically forage only short distances. This means that they are not efficient at carrying pollen over long distances
between their nests and the plants. .
Ants are great lovers of nectar. These busy insects are often observed visiting flowers to collect energy rich
nectar. They are more likely to take nectar without effectively cross-pollinating flowers.
Moreover, ants may be coated in some sort of antibiotics which may be detrimental to pollen. In some cases ants
steal nectar from flowers, causing damage and reducing the likelihood of later pollinators' visits. Some plants
resort to extra-floral nectaries, nectar-producing glands located in other plant parts, to keep the ants and other
nectar robbers away from the valuable treasure reserved for legitimate pollinators.
Ant on an aphid
covered plant stem
drinking honeydew.
Honeydew is a sugar-rich sticky liquid, secreted by aphids and some scale insects as they feed on plant sap.
When their mouthpart penetrates the phloem, vascular tissue in plants that conducts sugars and other
metabolic products downward from the leaves, the sugary, high-pressure liquid is forced out of the anus of the
aphid.
Why do aphids eject honeydew in the first place? Normally waste products of insects or animals are not
particularly appetizing except to dung beetles, fungus and bacteria. Yet honeydew is eaten by a wide variety
of insects and animals, and by humans. It is so prized by ants they actually tend their ‘herds’ of aphids and
protect them from predators to harvest their honeydew. Why don’t the aphids digest the honeydew as food
for themselves, or is it created perhaps as an incentive for the ant’s protection?
It turns out that while aphids use some of the sugars and other nutrients in the plant sap, they must process
a large amount of sap to get usable amounts of proteins. Plant sap only contains about 1-2% of proteins.
The rest is expelled and actually ejected away from the insect to land on leaves or needles, branches and
the ground below. If an aphid-covered branch is suddenly jostled they will release their honeydew in a fine
misty spray.
The flowers that are visited by ants are typically:
Low growing
Has small inconspicuous flowers
Has flowers that are close to the stem