Maize pest exploits plant defense compounds to protect itself

A new study by the Institute of Plant Sciences of the University of Bern and the Max Planck Institute for Chemical Ecology shows how the Western corn rootworm puts the maize plants' defense strategies out of action. The results explain why biological control of the crop pest has not been efficient. The Western corn rootworm continues to be on the rise in Europe. Why attempts to biologically target this crop pest by applying entomopathogenic nematodes have failed, can now be explained by the amazing defense strategy of this insect. In their new study, scientists from the University of Bern, Switzerland, and the Max Planck Institute for Chemical Ecology in Jena, Germany, show that the rootworm larvae are able to sequester plant defense compounds from maize roots in a non-toxic form and can activate the toxins whenever they need them to protect themselves against their own enemies. The western corn rootworm ( Diabrotica virgifera virgifera ) is a devastating pest of maize plants, which has spread throughout Europe. The insect originates from Central America, from where it spread invasively throughout North America since the 1950s.