1. Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
2. Nuclear Magnetic Resonance Department, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
3. Department of Entomology, University of Wisconsin–Madison, Madison, Wisconsin 53706
4. Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada