Annual Report 2006/07 - ETH - North-South Centre North-South ...

Research Fellow Partnership ProgrammeResearch fellow (Post-doc)Marco D’Alessandro,University of NeuchâtelSupervisorTed Turlings, University of NeuchâtelCollaboratorsGeorg von Mérey,University of Neuchâtel, /Kevin Pixley, Silverio Garcia, CIMMYT,Mexico / Jörg Degenhardt, JonathanGershenzon, Max Planck Institute forChemical Ecology, Jena, GermanyDurationMay 2007 – May 2009Exploiting scents of distress:Making maize plants more attractive to beneficial insectsnatural indirect defence mechanisms. When plants areattacked by insect herbivores they respond by emitting specificvolatiles that are highly attractive to the natural enemiesof the herbivores, such as predators and parasitic wasps, butwhich also induce defence mechanisms in nearby plants. Inmaize, there is exceedingly high variability in the quantitiesand qualities of induced volatile emissions between varietiesand this is also reflected in varying attractiveness to parasitoids.In previous work we were able to isolate a part of thetotal volatile blend that is extremely attractive to a key parasitoidin the laboratory.The entomology team at the CIMMYT station in Agua Fria near Poza Rica,State of Veracruz, Mexico (second from left: Georg von Mérey; third from right:Marco D’Alessandro)The fall armyworm Spodoptera frugiperda (Smith) (Lepidoptera:Noctuidae) is one of the most destructive insectpests of maize in the Americas, where it causes severe economiclosses to farmers. In Mexico, this pest is commonlycontrolled with synthetic insecticides, which pose hazards tothe environment and humans. Moreover, resistance has beenobserved and many small-scale farmers, whose existencestrongly depends on a yearly-granted maize yield, might notbe able to cope with an increasing need for insecticides. Thus,biological control of the fall armyworm is considered a highlydesirable alternative, especially in countries such asMexico, where the use of genetically-modified crops is currentlynot possible.We are currently applying this highly attractive blend inmaize fields in Mexico to demonstrate that the attractivenessof maize plants to beneficial insects can be enhanced.We will also compare the attractiveness of varieties thatshow differential amounts of attractive compounds andfinally we will identify the essential genes involved in theirproduction. Our close collaboration with molecular biologistsat the Max Planck Institute for Chemical Ecology in Jena andwith maize breeders of CIMMYT in Mexico should allow us toprovide the basis for the development of an ecologicallysound and sustainable fall armyworm control strategy.The aim of our project is to improve biological control inmaize against the fall armyworm by exploiting the plant’s60