Connect with us

Hi, what are you looking for?

Tech & Science

Artful caterpillars deceive corn plants

Researchers from Penn State College of Agricultural Sciences have been studying the dozens of chemical signals that pass between insects and plants. In doing so they have stumbled across a unique signal that caterpillars can produce in order to allow them to munch away at the leaves of the corn plant. Interestingly, the chemical is extruded from the caterpillar via its feces.

The caterpillars in question are fall armyworm larvae and the deposit they leave is called ‘frass.’ Frass accumulates near the bottom of the plant, where crevices in the leaves meet the stalks.

The findings that caterpillar poop has a modifying effect on corn plants has answered a riddle in biology: why do plants react against some insects and not others, especially in the case of aggressive and damaging attacks from caterpillars?

The answer is that the caterpillar does not switch off all defences. Instead, it gets the plant to orientate its defences against a different threat. Corn plants can produce chemical defences against insects or fungi but not both. Caterpillar frass triggers the plant into sensing that it is under threat from fungal pathogens. The plant alters its chemical pathways to fungi, leaving the caterpillar free to roam.

In some areas where fungal threats are greater, the researchers are considering whether the active substance from the frass can be used as a novel anti-fungicide to protect crops from molds. In early studies, the active substance proved effective against the fungus that causes leaf blight in corn (Cochliobolus heterostrophus). This was based on a small field study.

The findings have been published in the Journal of Chemical Ecology. The research paper is “Maize Plants Recognize Herbivore-Associated Cues from Caterpillar Frass.”

Written By

Dr. Tim Sandle is Digital Journal's Editor-at-Large for science news. Tim specializes in science, technology, environmental, and health journalism. He is additionally a practising microbiologist; and an author. He is also interested in history, politics and current affairs.

You may also like:


Global media in general doesn’t get this war. Just look at the headlines any day of the week.


Authorities in the US state of Ohio appealed for calm Sunday after releasing body camera footage that showed police fatally shooting a Black man.


The Supreme Court has asked state officials to enforce state laws that prohibit protests outside justices' homes.

Tech & Science

A green tea extract has been demonstrated as reducing the severity of radiation-induced dermatitis.