Dandelions Use Latex to Protect Roots From Hungry Insect Larvae

Posted on January 15, 2016

Hungry Cockchafer larva attacking roots of Dandelion

Dandelions are unwanted in lawns and gardens and can be difficult to get rid of. The hardy weed produces a latex, a milky bitter-tasting sap, that protects its roots against hungry insects, such as cockchafer larvae. An animation below shows the sap protection process in action.

Researchers from the Max Planck Institute for Chemical Ecology in Jena, Germany, and the University of Bern, Switzerland have determined that a single compound in the latex protects dandelion roots. The scientists found the highest concentrations of the bitter latex in the roots of dandelions. They tested the latex compounds to see if they were negatively associated with the development of cockchafer larvae. They found a substance identified as the sesquiterpene lactone, taraxinic acid β-D-glucopyranosyl ester (TA-G), that when added to an artificial larval diet made the grubs eat considerably less.

Jonathan Gershenzon, the head of the Department of Biochemistry at the Max Planck Institute in Jena, says in a statement, "For me, the biggest surprise was to learn that a single compound is really responsible for a defensive function. The latex of dandelions and other plants consists of such a mixture of substances that it didn't seem necessarily true that one chemical by itself had such a protective role against our study insect."

A research paper on the study can be found here in PLOS Biology. Here is an animation of a dandelion uses its latex to ward off a hungry cockchafer larva:



Photo: Meret Huber / Max Planck Institute for Chemical Ecology, PLOS Biology