Host plants tell insects when to grow longer wings and migrate
phys.org
phys.org
"It's all about the amount of glucose, or sugar, in the plant," Lavine said. "Rice plants with higher glucose levels are older and dying. That increase in glucose causes adolescent brown planthoppers to develop into the long-winged adults. The plant really is telling the insect how to grow."
The last sentence is just bad.
If plants had their way, they'd be telling the insect pests to GTFO from the get-go. The whole point is that plant sugar levels are an inevitable and reliable indicator of host status, with higher [glucose] indicating poor (and deteriorating) host quality. Evolution (in insect pest populations) by natural selection has led to insect populations evolving plastic developmental programs (Stay-or-go, via wing size) in response to that inevitable and reliable signal of deteriorating host quality.
But the conclusion that the plant is "telling" the insect something, rather than the insect adapting to changing conditions seems like a huge stretch. It's not like everytime an oil well dries up Mother Earth is telling us to start looking for other oil wells.
True though it should be a shorthand, convenient way of saying it, but I've seen it derail many a discussion when people get hung up on the abstract aspect.
> "Tell" might be something only humans can do or it might be more generally any signal from some entity that induces behavior in a living organism.
That's where it gets interesting because many times (though definitely not all), many of our communication is biologically or environmentally driven, so it's often tough even among humans what we're truly trying to communicate. It's a fascinating interplay between different parts of ourselves that we're trying to express :)