Nature can be extremely cruel in the most unexpected ways – especially when parasites are involved. As for the well-organized society of ants, some parasites have been known to subvert the existing social order to enslave their hosts. But new research suggests that this irritating behavior may not even be the most disturbing thing that parasitic ants are capable of doing.
In a paper published today in Current Biology, researchers describe how a parasitic ant queen tricks worker ants into killing their own queen – their mother. Such examples of matricide – a behavior in which an offspring kills or eats its mother – have been observed before in nature. However, this is the first time that scientists have observed matricide that benefits neither the mother nor the offspring but an unrelated, parasitic third party.
Too weird to be true?
A blog post by Taku Shimada, the study’s lead author and “avid ant enthusiast,” inspired the study, according to Keizo Takasuka, a senior author and entomologist at Kyushu University in Japan. Shimada filmed the parasitic ant species lasius orientalis Inducing matricide in host colonies, Takasuka explains to Gizmodo
This pattern deviated from previously known forms of parasitism in ant colonies, in which the attacking queen typically strangles or decapitates the host queen. In the post, Shimada was able to document the moment l. orientalisWhat are commonly known as “bad-smelling ants” in Japanese sprayed some kind of fluid on the queen.
“Then [intruder] Shimada’s article (translated from Japanese), quickly fled the premises. This was because “the spraying action also put the intruder at risk of being attacked, and you can see some of the worker ants biting the intruder.”
Shimada said that after a few hours of repeating this behavior, the dynamics of the colony began to change. Both queens were surrounded by worker ants – but the worker ants were chewing on their own queen while treating them intruder As their leader.
Shimada wrote, “The workers’ attacks became more violent as more fluid was sprayed on their real queen.” “What I found strange was that the worker ants, who were presumably sprayed with the fluid, were not attacked. It was only the queen. Could there be a secret hidden in this fluid? Being killed by your own daughters…”
“When I read the blog post, I was so shocked that I was at a loss for words for a while,” Takasuka said.
a mystery in progress
The new paper serves as a formal description of Shimada’s observations, which are coupled with several long-term experiments repeated by Takasuka and colleagues in the lab. According to the paper, during these tests, the team confirmed that the parasite species took advantage of the ants’ special sensitivity to smell.
The team has not yet chemically verified the composition of the fluid, although they believe it is likely some form of formic acid. The paper notes that invaders also rub up against host workers to mask their scent before infiltrating, revealing surprising sophistication in parasites. Overall, Takasuka said, this accidental discovery was “like the world’s platinum stamps that no one had seen before.”
“In temporary social parasites, killing the host queen is an important task, yet little is known about how it occurs because it occurs underground,” he said. “Life histories are full of surprising adaptive strategies, most of which remain unknown to us – often because they are hard to observe physically or cannot be understood from brief glimpses.”