All authors declare that no conflict of interest exists.


Prof Fredrik Schlyter, Chemical Ecology, SLU, Alnarp 
Mobile +46 708 73 53 33, home +46 46 2 11 51 48, office +46 40 415 303 
http://www.slu.se/fredrik-schlyter Skype: fredrik_schlyter 
www.slu.se/chemicalecology 
orcid.org/0000-0002-1244-0308