It’s true. As well as helping us humans to get up and at ‘em, caffeine has developed through evolution to deter insects from eating coffee trees and the like. Dubious? Read on…

As anyone who knows the difference between robusta and arabica will tell you, arabica grows at higher altitudes on mountainous plantations, while robusta hangs out around sea level. They’ll also tell you that robusta beans contain around twice as much caffeine as arabica beans. How are the two connected? Simple.


Insects prefer mild conditions to cool mountain terrain. They’re just not that rugged. Indeed, when our Head of Coffee goes on his coffee buying trips, he only needs to wear insect repellant when he arrives and leaves via the airport. During the time he’s up in the mountainous regions, meeting specialty coffee farmers and sourcing arabica, he doesn’t wear a single spritz of it.

Turns out that while mountainous arabica plants haven’t had to adapt to live among swarms of insects, robusta plants have. They’ve found over the years that caffeine deters little critters from trying to eat them, so they’ve made sure they’re chocker with the stuff.

As an aside, wondering why we don’t use caffeine as an insecticide for plants or an insect repellant for people? We did too; it turns out UV light degrades caffeine, plus it’s very water soluble. So if it’s merely sprayed onto a plant it would either be burned off or washed away by rain; it wouldn’t last long enough to make any difference.

So, next time you’re enjoying the day’s first caffeine hit, remember you have insects to thank for it.