Mutualism plays an important but underappreciated role
in the successful invasion by alien species, and can amplify
and diversify their impacts (Simberloff & Von Holle 1999;
Richardson et al. 2000). This may be especially so for
A. gracilipes and other invasive tramp ants which form close
mutualistic relationships with honeydew-secreting Homoptera
(Van der Goot 1916; Helms & Vinson 2002). Onforest ecosystem. These multitrophic-level distortions are
comparable in scope to those witnessed following deletion of
top consumers from tropical rain forest on man-made islands
(Terborgh et al. 2001). Furthermore, positive interactions
between this dominant, invasive ant and other introduced
species amplify and diversify impacts. Changes in the web of
interactions following multiple alien species introductions can
lead to synergism in invasive impact to precipitate invasional
meltdown (Parker et al. 1999; Simberloff&Von Holle 1999).