homehome Home chatchat Notifications


Farmer ants draft parasite ants as mercenaries

Ants are absolutely fascinating creatures. Not only have they discovered farming and animal husbandry thousands of years before us (sometimes even using bacteria to grow gardens), they also conduct executions for the good of the colony, follow Fermat’s principle of least time, and as it has been shown now, draft parasite ants as mercenaries. Just […]

Mihai Andrei
September 10, 2013 @ 6:11 am

share Share

Ants are absolutely fascinating creatures. Not only have they discovered farming and animal husbandry thousands of years before us (sometimes even using bacteria to grow gardens), they also conduct executions for the good of the colony, follow Fermat’s principle of least time, and as it has been shown now, draft parasite ants as mercenaries.

Just like medieval cities sometimes recruited expensive contingents of mercenary soldiers to ward off invaders, farmer ants sometimes recruit parasite warrior ants to fight for them, as it is neatly illustrated by this video.

Entomologists investigated a type of ants called Sericomyrmex, which raise fungus in gardens. They are what you would call farmer ants, living on peacefully in their day to day activities. But they have a problem with a type of parasitic ants named Megalomyrmex. These species has cunning queens which stealthily enter and colonize the gardens of Sericomyrmex and can feed on their offspring and their fungus for years before they are detected and stopped. They even cut off the wings of the virgin queens of Sericomyrmex, thus halting the spread of further colonies.

Evolutionary biologist Rachelle Adams at the University of Copenhagen has studied this stunning phenomena for over 10 years; she noticed that at some point, these parasites can make up to 80 percent of the entire colony, which doesn’t really seem to make any sense.

“This prompted me to question why this might be, leading me to focus my collecting efforts on this particular system,” Adams said.

So she put ants to the test: she took the farmer ants and exposed them to another common threat to them: Gnamptogenys. This is also a type of parasitic ant, but they’re way more threatening: they come, pillage the fungus gardens and destroy everything. However, when exposed to this threat, while the farmer ants went into hiding, the Megalomyrmex rose up and fought the invaders off – and then it hit her! Sometimes, they are not truly parasitic, but instead, are fed and tolerated in order to protect the colony.

Copyright: Anders Illum.

Copyright: Anders Illum.

“The guest ants are the better of two evils,” Adams explained. “If the raiders were not a threat, then the guest ants would only be a burden to the host colony.”

Indeed, this theory was confirmed by further research – she noticed that invaders only attack colonies without ‘mercenaries’.

“If we studied just the farming ants and the guest ants, we would have missed this important discovery and concluded the guest ants are simply parasites,” Adams said. The researchers compared this tradeoff to sickle cell anemia, a hereditary blood disease that can cut lives short but also gives people resistance against malaria.

The research team also highlighted that Megalomyrmex conducts a type of chemical warfare.

“The raider ants attacked by the Megalomyrmex were often attacked by their own nest mates,” Adams said. “This suggests that the guest ant venom disrupts the recognition system of the raiders, causing sisters to attack and kill one another.”

This just goes to show that relationship between ants, and likely other insect species are simply far more complex than we have judged them so far. We should keep in mind that every additional interaction brings an entirely new complexity and should change the way we perceive the situation.

The scientists detailed their findings online Monday in the journal Proceedings of the National Academy of Sciences.

share Share

Underwater Tool Use: These Rainbow-Colored Fish Smash Shells With Rocks

Wrasse fish crack open shells with rocks in behavior once thought exclusive to mammals and birds.

This Freshwater Fish Can Live Over 120 Years and Shows No Signs of Aging. But It Has a Problem

An ancient freshwater species may be quietly facing a silent collapse.

Sharks Aren’t Silent After All. This One Clicks Like a Castanet

This is the first evidence of sound production in a shark.

Earth’s Longest Volcanic Ridge May Be an Underwater Moving Hotspot

Scientists uncover surprising evidence that the Kerguelen hotspot, responsible for the 5,000-kilometer-long Ninetyeast Ridge, exhibited significant motion.

This Medieval Bear in Romania Was A Victim of Human Lead Pollution

One bear. Six years. One hidden history of pollution brought to light by a laser.

New NASA satellite mapped the oceans like never before

We know more about our Moon and Mars than the bottom of our oceans.

Some 31 million years ago, these iguanas rafted over 5,000 miles of ocean

New research reveals an extraordinary journey across the Pacific that defies what we thought was possible.

Magnolias are so ancient they're pollinated by beetles — because bees didn't exist yet

Before bees, there were beetles

The Arctic Seafloor Is Full of Life — And We’re About to Destroy It

The Arctic Ocean is more than just icy waters, it harbors vibrant ecosystems — but it also harbors valuable oil, gas, and rare earth elements.

Venomous love: These male octopuses inject venom into females so they can escape being eaten

In the perilous world of cephalopod romance, male blue-lined octopuses have evolved a shocking strategy to survive mating.