“Evolution of increased competitive ability in
invasive nonindigenous plants: a hypothesis”
by Bernd Blossey and Rolf Notzold
1995
EICA: Evolution of Increased
Competitive Ability
1. Optimal Defense
2. Specialized Herbivore Performance
What is the EICA hypothesis?
Simply put:
-Without native predators, introduced plants are able to reallocate
defense mechanism resources and focus on their growth and development
Specialized Herbivores will perform better because the plants have
limited defense.
Lythrum salicaria
-Seeds collected from native and
invaded environments
-Herbivorous insects tested
Blossey, Notzfold, 1995
Was the EICA hypothesis supported?
Collected data from various articles using
Google Scholar, Web of Science, UMass Library
Databases
Overall, support for
the hypothesis
was strong
Literature Support
“No evidence for an ‘evolution of increased
competitive ability’ for the invasive Lepidium
draba” Cripps et al. 2008
All plant traits greater in native plants
Proposition?
Can
generalizations be
made?
Joshi, J. and Vrieling, K. (2005), The enemy release and EICA hypothesis revisited: incorporating the fundamental
difference between specialist and generalist herbivores. Ecology Letters, 8: 704–714. doi: 10.1111/j.14610248.2005.00769.x
Bossdorf, O., Prati, D., Auge, H. and Schmid, B. (2004), Reduced competitive ability in an invasive plant. Ecology
Letters, 7: 346–353. doi: 10.1111/j.1461-0248.2004.00583.x
Fukano, Y., & Tetsukazu, Y. (2012). Changes in Defense of an Alien Plant Ambrosia artemisiifolia before and after the
Invasion of a Native Specialist Enemy Ophraella communa. MULTIDISCIPLINARY SCIENCES, 7(11). Retrieved
October 16, 2014, from
http://apps.webofknowledge.com/full_record.do?product=WOS&search_mode=Refine&qid=10&SID=4DOmUeua3qHke
SwQGa1&page=1&doc=6#
"EICA Hypothesis." Wikipedia. Wikimedia Foundation, 22 Aug. 2014. Web. 21 Oct. 2014.
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