Biological control of the floating fern Salvinia molesta in north-eastern Australia: plant-herbivore interactions

The curculionid Cyrtobagous salviniae Calder & Sands and the pyralid Samea multiplicalis Guenée were released in north-eastern Australia for the biological control of the floating fern Salvinia molesta. C. salviniae destroyed large areas of weed and was successful at coastal and elevated sites. At equilibrium, there was less than 1 adult/20 plants and only a few, very small plants at each site. The rate at which the weed was controlled varied with mat density. The moth did not reduce plant growth permanently at any site and did not interfere with the performance of the weevil.