Scientists say they’ve for the primary time unlocked how a parasitic ant makes use of chemical warfare to take over the nest of a special species, by tricking workers into an unlikely assassination.
The lethal scheme unfolds like a Shakespearean drama. In an ant colony, the queen is dying, beneath assault by her personal daughters. Meanwhile, the true enemy — an invader queen from one other ant species — waits on the sidelines. Her plan is easy: Infiltrate the nest and use chemical weapons brewed inside her physique to deceive the employee ants into mistaking their rightful ruler for an imposter.
In a couple of hours, the nest’s queen will fall. Once the previous matriarch is useless, the invader will assume the function of the colony’s new chief.
Matricide in an ant colony shouldn’t be extraordinary — it usually occurs when a colony produces a number of queens or when a solo queen reaches the tip of her fertility. But this explicit situation, by which an outsider queen turns workers into her proxy assassins, has by no means been described intimately earlier than, researchers reported Monday within the journal Current Biology.
In truth, this technique is but to be documented in another animal species, stated the examine’s senior creator Dr. Keizo Takasuka, an assistant professor within the division of biology on the University of Kyushu in Japan.
“Inducement of daughters to kill their biological mother had not been known in biology before this work,” Takasuka instructed NCS in an e-mail.
The researchers noticed this habits amongst ants within the Lasius genus, documenting invasions and employee manipulation by queens within the species L. orientalis and L. umbratus.
“Prior studies had reported that, after a new L. umbratus queen invaded a host colony of L. niger, host workers killed their own queen,” Takasuka stated. “But the mechanism remained entirely unknown until our study.”
Ants talk by way of scent, which is how they distinguish between nestmates and foes. When researchers beforehand noticed parasitic ant queens close to a colony’s foraging trails, they noticed that the parasite would snatch up a employee ant and rub it on her physique, disguising her scent and permitting her to slide into the nest undetected.
For the brand new examine, coauthors Taku Shimada and Yuji Tanaka — each citizen scientists in Tokyo — every raised an ant colony and launched parasitic queens. Shimada noticed an L. orientalis queen in an L. flavus colony, and Tanaka recorded an L. umbratus queen invading a colony of L. japonicus.
In each experiments, the scientists first co-housed an invading queen with host workers and cocoons “so that she acquired the nestmate odour,” Takasuka stated. “This allowed her to gain nestmate recognition and avoid retaliation upon entry.” The scientists then launched the queen into the colony.
Both parasite queens adopted an identical plan of assault. After disguising their scent, the queens entered the colonies’ feeding areas. Most workers ignored the interloper. Some even fed her mouth-to-mouth.
But the invading queens weren’t there for dinner — that they had an assassination to set in movement. After finding the resident queen, the invader sprayed her with stomach fluid that smelled of formic acid. The scent agitated workers, with a few of them turning on their queen instantly and attacking her. Multiple sprays adopted, and the assaults grew to become extra brutal.
“The host workers eventually mutilated their true mother after four days,” the scientists reported.
The loss of life of the true queen was the invader’s cue to begin producing a whole lot of eggs, attended by her newly adopted “daughters.” Over time, her organic daughters would quantity within the 1000’s, usurping the colony till not one of the authentic species remained.
“It’s refreshing to see a very careful observational study that discovers something interesting that we — ‘we’ meaning ant researchers — suspected but had never confirmed,” stated Dr. Jessica Purcell, a professor within the division of entomology on the University of California, Riverside.
“I was really struck by this discovery, especially the use of a chemical compound to elicit that behavior by the workers,” stated Purcell, who was not concerned within the analysis.
Social bugs like ants collect and retailer assets for the colony to share. That makes them a beautiful goal for social parasites — species searching for well-stocked nests that they’ll exploit. Some ant species kidnap the colony’s offspring and enslave them. Others, akin to L. orientalis and L. umbratus, arrange store within the colony, the place they get rid of the prevailing queen and take her place.
“There’s all of this amazing diversity,” Purcell instructed NCS. “What we didn’t know a lot about before this study, is the various ways that socially parasitic queens might go about assassinating the host queen. People had done some observations of direct killing where the infiltrating queen would go and cut off the head of the existing queen. But this is astonishing that they can actually use chemical manipulation to cause the workers to do it.”
Violence inside households is commonly described in fairy tales and myths, with depraved adults — usually determined dad and mom or jealous stepparents — conspiring to hurt or kill youngsters. Rapunzel is imprisoned in a tower; Snow White is hunted after which poisoned by an apple; Hansel and Gretel are deserted within the forest and captured by a witch, who imprisons them and fattens Hansel for her supper.
But whereas such tales embody loads of violence, the killing of a mother in folklore — not to mention youngsters being tricked into matricide — is nearly nonexistent, stated Dr. Maria Tatar, a professor emerita of folklore and mythology at Harvard University who was not concerned within the new examine.
In that respect, Takasuka famous, the grim story of the invading, manipulative ant queens stands out much more.
“Sometimes, phenomena in nature outstrip what we imagine in fiction,” he stated.
Mindy Weisberger is a science author and media producer whose work has appeared in Live Science, Scientific American and How It Works journal. She is the creator of “Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control.”
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