About 70% of all ant species have a stinger that they use to, well, sting: it’s a tool used to deliver poisons and other toxins by penetrating the target’s skin or armor.
There are a few exceptions to this rule, and the latest one we’ve discovered might be the strangest: the ant Lordomyrma azumai it uses its stinger to secrete… a thread, a bit like spiders do. The story is obviously more complicated than that, and is told in a study, still in preprint, published on bioRxiv.
The ant that when it attacks… attacks
Lordomyrma azumai it lives in Japan, and is a relatively rare ant: discovered and described in the 1940s, it has never been studied in depth, and in particular we knew nothing about its peculiar method of defense against intruders.
Which could resemble that of spiders: the workers of this ant, when they have to protect the colony, emit from their sting a thread of a still unidentified substance (“probably proteinaceous” we read in the study) which solidifies in contact with the air, trapping the invader.
Where other ants use their stinger to inject venom into intruders and prey, therefore, Lordomyrma azumai he prefers to immobilize them in place… and here our knowledge of his “superpower” ends.
The discovery is in fact brand new, and is only the beginning of a journey of in-depth knowledge of these ants: we still don’t know what they do once the invader has been immobilized, for example, or whether its sticky thread is still toxic or just a way to trap an unwanted guest.
Sticky and poisonous?
The answer to this second question can only come with experimental studies and analyzes of the substance produced by these ants, but the authors of the study explain that there are clues that lead in this direction.
The strongest is related to another genus of ants, Crematogasterwhose stinger is not pointed but spatula-shaped: they use it to “smear” invaders with their venom, which in contact with the air takes the form of a toxic foam which, in certain species, can even lead to the death of the animal that is covered by it.
The case of Lordomyrmahowever, is a little different: in the study we read that «according to our knowledge, there are no other hymenoptera (therefore not only ants but also bees, wasps…, ed.) that secrete a solid thread».
And according to Hajime Sasaki, first author, «the secretion of these ants literally glues the invader to the ground: as such it is a very effective defense weapon, even if the thread were not poisonous».
