Plants As 'Green Phones'

According to new research, plants act as a telephone service for insects. Null's Wisconsin reporter, Ryan Kresse, explains how creepy crawlies tap into the green network.

It’s late. You’ve had a rough day. You’re exhausted. But the upstairs neighbours are driving you mad with a horrible party that won’t end. Are they mating? Are they molting? Are they eating the roof?

If you’re a subterranean, root-eating insect, you can do something about it. You can turn the plant you live under into a telephone and tell your annoying, upstairs, leaf-eating neighbours to bugger off.

Roxina Soler, an ecologist at the Netherlands Organization for Scientific Research, explained how insects use plants to communicate. “Plants can act as green phones, bridging interactions between insects that live in the often ignored soil ecosystem and insects that live in the aboveground
ecosystem,” Soler told the Null.

When plants are attacked, they release chemicals called phytotoxins, which affect the development of both aboveground, leaf-eating insects and subterranean, root-eating insects. Soler's new study shows that insects use these chemicals as warning signals that competing insects are about. Phytotoxins effectively say, "Get offa my plant!"

Plants also have their own messaging systems. Those not infested by root-eaters are better able to send out chemical signals that attract parasitic wasps. These signals let the wasps know that there are plenty of healthy hosts in which to lay their eggs. Wasp offspring develop more slowly if their hosts are exposed to phytotoxins, so the wasps ‘sniff out’ and avoid plants that are infested with root-eating insects. .

“Plants, herbivorous insects, and parasitic wasps are involved in a complex of direct and indirect interactions, mediated by chemicals,” said Soler.

So if you're an aboveground, leaf-eating insect, you have a dilemma. You can fight over a plant inhabited by root-eaters, or you can find a plant with undamaged roots and risk what might be the most horrible death in Nature - being slowly eaten alive from the inside by wasp larvae. If only you could use the plant-phone to call someone.

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