EVOLUTION. For the article “Increase in toxicity of an invasive weed after reassociation with its coevolved herbivore,” by Arthur R. Zangerl and May R. Berenbaum, which appeared in issue 43, October 25, 2005, of Proc Natl Acad Sci USA (102:15529–15532; first published October 17, 2005; 10.1073/pnas.0507805102), the citation given for ref. 6 contained the incorrect volume number. The online version has been corrected. The correct reference appears below.
6. Hierro JL, Maron JL, Callaway RM (2005) J Ecol 93:5–15.