I have seen a lot lately about ants
(called ‘formigas’ in Portuguese) being a problem as they furiously dig holes
and take food back into their nests, eating just about anything. There are more
than 10,000 types of ants, and their diet includes sugary nectar, as well as
dead insects, seeds, plants, and fungus. Ants also drink water, which they find
in sources like dew.
Here in Portugal, we are blessed with a
lesser number than that - phew, I hear you exclaim, but there are more than
enough different types here thank you very much, and all of them are really
ugly close-up, with faces only a mother could love.
Apparently, there are around 34 species
roaming underground here and include the dreaded fire ants that will bite you,
or rather sting you. Being very aggressive when their nests are disturbed, they
will swarm on an intruder, anchor themselves by biting to hold the skin stable,
and then sting repeatedly, injecting a toxin alkaloid venom called solenopsin.
Another species here is the Carpenter
Ant usually found in forests, and get their name because they excavate wood in
order to build their nests. Of all ant species they are one of the most
problematic and can cause serious property damage to homes and other buildings.
Common or Pavement Ants are the ones we
probably see the most. They have many queens and will nest under rocks or in
pavements as they mine the sand and soil from under concrete slabs, patios,
pavements and driveways. These ants are all one size and do possess a stinger,
but generally a person is not stung easily unless they catch you when you rest
an arm or leg over a nest, as in a lawn.
These ants will also forage into your
home for food items and will feed anything sweet or greasy. Because these ants
nest underground and have multiple queens, there have been problems with
management. They like to nest in places that are dry and easy to tunnel
through, and loose soil in outdoor containers is a prime target - if soil falls
out of a dry pots’ drainage holes, it presents the perfect area for a colony to
start building a nest.
The simplest way to prevent ants from
nesting in potted plants is to keep the soil moist, and if the pot dries out
completely, just soak in water, and let it drain.
While it’s normal to have ants in a
garden, sometimes they can be a sign of bigger problems. Ants are attracted to
the sweet sap that is expelled from plants when pests like aphids feed on them,
so if you see ants in your garden beds or pots, you may want to follow them to
see where they’re going.
Garden ants do not eat plant roots but
will tunnel or build their nests in and around the roots because the soil is
generally looser there. Most of the time, the ones crawling on the leaves are
feeding on the sweet sap produced by other pest damage.
Here’s something interesting about ants
too - the largest ant colony in the world has been discovered in southern
Europe. From the Atlantic coast of Spain to Mediterranean Italy, invading
Argentine Ants recognize and treat each other as if they were from the same
nest, despite being unrelated. The European invaders formed an unusual
supercolony, with workers moving freely between nests and gathering food for
unrelated queens.
To test the size and theories, experts
captured ants from 33 places across coastal southern Europe and performed
behavioral and genetic tests. First, they put pairs of ants from different
locations together and checked for signs of aggression, and ants from 30
locations across Europe showed no aggression towards each other (although they
fought with ants from a splinter supercolony in eastern Spain).
Genetic studies of Argentine Ants
suggest that cooperation arose by accident, when the introduced population
passed through a genetic bottleneck, making them unable to recognise friend or
foe. My mind boggles at the thought of being taken over by ants, or southern
Europe collapsing into one huge nest!
Marilyn writes regularly for The Portugal News, and has lived in the Algarve for some years. A dog-lover, she has lived in Ireland, UK, Bermuda and the Isle of Man.
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