Highwaymen Beetles Hold Up Ants To Steal Their Food In A Really Gross Way


The beetles have exploited a behavior in ants, and now use it to steal the food directly from their stomachs. Hölldobler et al. 2017

You might think you have bad eating habits, but at least you’re not eating someone else’s puke. It turns out that one species of beetle does exactly this, and gets the majority of its food by making ants vomit directly into its mouth.

The beetles (Amphotis marginata) actually exploit a behavior that is common to many species of ants, in which the insects will feed other ants from their colony in the rather charming fashion of regurgitating into each other’s mouths, a process that is technically known as "trophallaxis".


“It's that behavior that this parasitic beetle has sort of capitalized on,” explained Christina Kwapich, who co-authored the study published in PLOS ONE. “It's broken the code of communication between the ants in order to steal that sugary liquid that's meant for other nestmates.”

The researchers discovered that the beetles will sit along the edges of foraging trails made by the ants, and then solicit the workers stuffed with honeydew as they pass by.

“We refer to them as highwaymen beetles, because they're robbing the traffic lines of the ants,” joked Kwapich. But the beetles are so good at this chunder deception that they are actually able to get the unfortunate ants to vomit more than they would when feeding a fellow nestmate.

Arizona State University 


The beetles manage to get the ants to barf using some fairly intense trickery. First of all, the beetles tap and caress the ants with their antennae, whilst secreting an attractive chemical from their heads. This beguiles the ants into staring into their faces and licking their heads. The beetles stimulate them to open their mouthparts and extend their labium (lower lip), getting the unfortunate ants to puke directly into their mouths. Delicious.

In effect, the beetle seduces the ant before sticking its fingers down its throat.

Using radioactive honeydew, the researchers were able to track the puking of food between the ants and the beetles. By doing this, they figured out that the hoodwinked ants regurgitated 1.8 times more liquid to the beetles than they do to their own kind. The researchers were also able to note that the beetles never gave food back to the ants, making it a case of pure parasitism.

The rather unusual lifestyle does not, however, come without risk. If the beetles make a mistake, and the ants realize that they are not in fact other ants wanting a meal but beetles slurping on their hurl, the ants will flip the beetles over and literally tear them limb from limb.


So, if the choice is being torn apart or eating vomit for the rest of your life, I think the answer is pretty clear.

[H/T: New Scientist]

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