Do you think your parents were overprotective when you were growing up? Think again. A new kind of wasp was found deep in the forests of China, and it uses the bodies of dead ants to protect its babies from the big, bad world.
The wasp does not visually match any other known wasp in its genus, Deuteragenia, and it's the only one known so far to keep its offspring in nests hidden by ant corpses.
Michael Staab is trying to understand the forests of China for a large ecology project from the University of Freiburg. It was during this project that he encountered the strange species of wasp, which he then named Deuteragenia ossarium, or the bone-house wasp, as a tribute to old European "bone-churches" called ossuaries that contain piles of human skeletons.
Staab and colleagues published their findings in the journal PLOS ONE on July 2. The researchers describe how the bone-house wasps collect ants-still alive or already dead is still a (gruesome) mystery-and use their corpses as nest protection blocks.
While the method was likened to European bone-churches, the protection offered by the corpses was likened to that of the Great Wall of China. Nests protected by these corpse plugs were significantly less vulnerable to predators and other natural threats than nests, such as those made by different wasp species, without the plugs.
As per Staab one of the advantages of dead ants over, say, other dead things, is the smell. Ant carcasses are apparently quite pungent and can camouflage other scents or deter predators. The authors of the paper believe this is because ants, like the bone-house wasps, are also fiercely protective of their young.
Staab made artificial nesting zones for the wasps by placing hollow canes in strategic places. Female wasps quickly took these canes and made them their own, building nests in 829 of them. The nests were split into brood cells for the young, each cell separated by dead spiders that would be the young wasps' first meals after hatching.
During development the wasps cocoon within their cells. In this state they would be left wide open to any natural dangers, but Staab noticed that 73 of the nests were corked with as many as 13 ant carcasses. When the wasps from those nests emerged from their cocoons, Staab saw that they looked unlike any other wasp in the region (they were completely pitch-black), and so suggested the novelty of the bone-house wasp as a species.
As for the question of whether the bone-house wasps find and kill live ants for protection or take the gravedigger route, Staab predicts that the wasps actively hunt live ants since the corpses seemed quite fresh.
"The discovery of a new species raises new questions. We want to understand why biodiversity is important for a functioning ecosystem," says Dr. Alexandra-Maria Klein, co-author of the paper.
