Fruit flies can communicate with each other

There's a nice little view from the institute roof where in summer it's interesting to watch the butterflies. I imagine that a butterfly perceives the world quite differently to me - their eyes must be much smaller and therefore of much lower resolution, they must feel the effects of smaller breezes much more intensely than I do (though the wind level they can fly in is surprisingly high). One butterfly on its own is like watching a goldfish : sort of relaxing, but not terribly interesting. A little bit of flapping followed by long periods of aimless gliding, generally staying in the same area with no obvious driving goal. Get two together and things change. Once they get within a certain distance - I don't know whether they're seeking each other out somehow or it's just chance - their flight pattern instantly goes into a series of tight crazy spirals and larger loops, soaring and diving and occasionally chasing each other at longer distances, alternating with astonishingly fast reaction times. You'd need a slow-motion camera to analyse it properly. However rudimentary, some form of cognition appears to be at work in these tiny critters. And now I find out that fruit flies can communicate with each other...

Fruit flies from different species can warn each other when parasitic wasps are near. But according to a new study led by Balint Z. Kacsoh of Geisel School of Medicine at Dartmouth, published July 19th in PLOS Genetics, they are more likely to get the message across if the fly species have previously cohabited and learned each other's dialects.

 Previous experiments from Bosco's group showed that females use wing movements to communicate the threat of the wasps to other females, who will then lay fewer eggs, despite never having seen a wasp. In the new study, the researchers tested whether fruit flies from different species could communicate that wasps are near. They found that when testing distantly related flies could not communicate as effectively as flies of the same species, but that communication improved when the two species cohabitated. Living together enabled the flies to learn new dialects composed of different visual and scent cues. Further genetic experiments showed that learning another dialect requires a part of the brain called the mushroom body, which is the center of learning and memory in flies.

[I remain convinced that at least some animals possess a true language, even if not necessarily as complex as human language. However, I would be surprised if their language was purely oral - instead it will rely on other sensory cues such as body movement, scent, etc. Why should not syntax be encoded in gestures or a scent ?]

https://www.sciencedaily.com/releases/2018/07/180719142014.htm