Quinine is not just found in the Cinchona pubescens trees.  Amazingly enough quinine is produced by a bug called the Bombardier Beetle.  The beetle has two chemicals in its body which are called hydrogen peroxide dissolved in water and hydroquinine.  If both of the chemicals were mixed, the peroxide would oxidize the hydroquinine.  However, this does not happen.  The beetle contains an inhibitor which blocks the oxidation from occurring.  These two chemicals are able to mix in the combustion chamber of the beetle without any reaction occurring.  When a predator approaches, the beetle uses two enzymes called catalase and peroxidase to produce quinine.  When the quinine is formed, it gives off a very foul odor.  The foul smell, as well as the combustion chamber exerting enough pressure to squirt out its contents at an amazing 500 pulses per second at 212 degrees Celsius kills the predator!

Quinine is also used in a much similar way in protecting the Cinchona pubescens.  Quinine is an alkaloid which is derived from the bark of the tree.  Alkaloids have a variety of effects on the metabolic functions of humans and animals.  More importantly, quinine has a very bitter taste which is helpful in keeping the predators away.

An experiment conducted by John Skelhorn and Candy Rowe from the University of Newcastle assessed how predators are affected by the chemical defenses of the prey.  Basically, the scientists set up two cages with baby chicks in each.  Quinine and bitrex are both chemicals that are bitter-tasting to chicks.  Bread crumbs were sprayed with quinine and bitrex and also water.  The quinine and bitrex sprayed crumbs were then colored red and the water sprayed crumbs were colored green.  The findings of the experiment concluded that the birds were not able to distinguish between the different colored crumbs.  The rate of attack on the bread crumbs was the same for all of the groups, but the chicks ate a higher proportion of the green crumbs.  This information can be used to infer that quinine in Cinchona pubescens is an adaptation used to keep predators from attacking it.  To learn more about the details of this experiment, visit Biology Letters.

To find out how the fever tree is able to attain its nutrition to survive, go to Nutrition.

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