These stealthy survival tactics could teach us how to curb the widespread use of chemical pesticides in agriculture. But first, researchers must learn how seemingly helpless flora deploy this masterful strategy, writes Tim Vernimmen in an article published by Knowable Magazine.
Vernimmen writes that plants may seem defenseless against insects, having neither hands nor tail to brush them away. But many produce potent repellent chemicals, ranging from ones that just taste or smell bad to ones that can kill.
These disgusting compounds work well against nibbling and sap-sucking insects that feed on a wide range of plant types, as well as grazing and browsing mammals. Yet inevitably, over the course of evolution, certain animals specialized to the point that they’re now attracted to even the most repulsive stuff that plants have come up with. In fact, many of the crops our own species grows for consumption, from tobacco to coffee to coriander, appeal to us precisely because of the compounds they produce to discourage herbivores.
So, what’s a poor plant to do then?
Some, through natural selection, have evolved a different strategy aimed at dispatching unwelcome visitors: They send out odor signals to attract their enemies’ enemies. Depending on the signal, various members of a motley crew of self-interested creatures may respond. Some devour the plant eaters, while some simply deposit their eggs in them and let their larvae finish the job. Others bring in deadly bacteria.
Chemical ecologist Ted Turlings of the University of Neuchâtel in Switzerland has been studying this bag of tricks for over three decades, in various spots around the world. A better understanding of these natural solutions, he believes, may help us to reduce our use of chemical pesticides, which are a threat not only to many potential insect allies, but also to human health.
Turlings and coauthor Matthias Erb of the University of Bern described the intriguing chemistry between plants and the organisms that protect them from pests, and how we might use it to our advantage, in the Annual Review of Entomology.
Source: Knowable Magazine. Read the original full-length article here
Photo: Colorado potato beetle. Credit Pavlo from Pixabay
