See: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2634150/ and http://en.wikipedia.org/wiki/Inducible_plant_defenses_against_herbivory I'm sure there are others, but the wikipedia page gieves a decent explanation of metabolic cost/risk/reward for inducible and permantent defences. Jeremy West Michigan *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html