62 Nebraskaland • October 2023
THE LAST STOP
With more than 15,000 described
species of ants, as noted in "Bolton's
Catalogue of the Ants of the
World," these organisms are among
the world's most successful and
represent a total estimated biomass
of 12 megatons. They have also
long been the subject of amateur
naturalists and scientists, with
perhaps no behavior more intriguing
than the "farming" of aphids.
Aphids are commonly known
to gardeners as a pest. They
suck nutritious juices from plant
stems, causing crop damage and
transmitting plant diseases. This
plant-sucking characteristic is
precisely why ants value aphids.
Ants have been shown to raise
aphids in order to harvest their
sugar-rich waste secretions known
as honeydew. This relationship is
symbiotic, because aphid colonies
collapse when ants are removed.
So, what benefi t do the ants provide
the aphids? Ants are not the only
species hungry for the sugary rich
fl uids of aphids. Instead of consuming
the honeydew, predaceous insects,
such as lady beetles or syrphid fl y
larvae, squish aphids and suck out
their juices. Ants protect their fl ock
of aphids by aggressively warding off
aphid predators. In fact, aphids have
been shown to secrete dopamine
in their honeydew to increase ant
aggression.
I watched this syrphid fl y larva
capture, squish and desiccate this
aphid over the course of several
minutes. All the while, a pair of ants
patrolled the larva and sampled its
scents with their antennae.
I did not witness any aggression
toward the syrphid fl y larva by
the ants. Perhaps the single aphid
casualty was an acceptable loss. Or,
alternatively, perhaps the ants had
already returned to the colony with a
pheromone trail leading back to the
larva. If so, I would not expect the
syrphid fl y to last much longer.
Even the most voracious insects
are no match for a colony of ants.
By Tyler Moore, Bellevue University
PROTECTING THE FLOCK
TYLER MOORE
