About a year ago, the botanist KO Mochizuki of the University of Tokyo has described a new plant species, Vincetoxicum nakaianumnative of Japan. After a year, this plant returns to the protagonist of a study by the same author, because it has an exceptional feature and never seen before in the plant world: it is capable of imitating the smell of ants to attract their predators, and exploit them as pollinators. The discovery is described in a study published on Current Biology.
Predators but also pollinators. The discovery took place almost by chance: Mochizuki tells, which was working on a research project on another plant, using some specimens of the new species as a comparison. Observing them, however, he noticed that several insects of the family piled up on their leaves Chloropidaenotes in English as “mosses of the grass”. These small flies are opportunistic predators: they go in search of ants already injured (for example from a spider) and eat them. Since often these ants are on the flowers of Vincetoxicum nakaianumthe muscles that visit them also perform, involuntarily, an pollination service.
A particular smell. Faced with the scene of dozens of flies that jumped around “his” plants, Mochizuki therefore decided to test his hypothesis, subjecting the flies to a series of smells, including that of ants attacked by spiders (who apparently have a different smell than the ants attacked by other animals). He discovered that these insects are attracted in particular by this smell, and an informal research on social media has confirmed that it often happens to see, in nature, ants that are attacked by spiders and are then devoured by the flies.
The deception of the wounded ant. Summarizing the order of events, therefore, things go like this: an ant is attacked by a spider, and wounded or killed. The grass flies catapult themselves to the corpse to feed on it. In this context it fits Vincetoxicum nakaianumwhich has learned to produce the same smell that ants make when they are affected by an arachnid. In this way, the plant attracts flies, which by visiting the flowers collect pollen and contribute to distributing it.
Only the beginning. This is the first interaction of this type never documented in nature: no other plant (as far as we know) has learned to imitate the smell of an ant to be pollined by another insect again. Mochizuki is also convinced that there are other similar examples, which have simply not yet been discovered: his next studies will focus on this.
