Dispersal of Galerucella pusilla and G. calmariensis via passive water transport in the Columbia River Estuary

Biological control as an invasion process: disturbance and propagule pressure affect the invasion success of Lythrum salicaria biological control agents

“…This relationship is unlikely to reflect a negative influence of disturbance on the host plant as loosestrife forms dense stands along the entire reach of the LCRE and along both island and mainland shorelines. The influence of disturbance is therefore more likely to be a direct affect on the insects themselves through dislodgment (Ferrarese and Garono 2010). Mainland sites may provide more refuge opportunities for overwintering insects to retreat from inundation, thus allowing populations to persist and reach higher abundance than island sites.…”

“…In addition, Albright et al (2004) found that in a single season Galerucella had dispersed 9 km from the release site and Grevstad and Herzig (1997) found that Galerucella could locate and colonize loosestrife populations up to a kilometer away within a 7-day period. Ferrarese and Garono (2010) calculated that beetles could be passively transported in the bidirectional water flow in the LCRE by as much as 3.8 km upstream or 12 km downstream during one tidal exchange. They also found established Galerucella populations 3-5 km from known release sites.…”