1 Integrated control 2 What is biological control? Water lettuce - PDF document

Aquatic weed management in the Sand River Catchment Sand River Catchment Chandre L Rhoda & Chandre Rhoda & Louise Stafford Louise Stafford Aquatic weeds in the Sand River Catchment Red water fern Kariba weed Azolla filiculoides Salvinia molesta Water hyacinth Eichhornia crassipes Water lettuce Parrot’s feather Pistia stratiotes Myriophyllum aquaticum 1

Integrated control 2

What is biological control? Water lettuce – Neohydronomus affinis Using host specific natural enemies (insects, pathogens) to control invasive weeds It is not a quick fix Long-term (5 – 10 years) Sustainable, cost effective, environmentally friendly Works best when combined with other methods Monitor, evaluate, adapt Parrot’s feather – Lysathia sp Salvinia – Cyrtobagous salviniae 3

Relying 100% on biological control during Azolla – Stenopelmus rafinasus western leopard toad breeding season Mocke River Mocke River After Lysathia Before Lysathia 4

Bio-mass removal • Aquatic and Terrestrial weeds • Rubbish Re-vegetation – Westlake River Re- vegetation Keyser’s River 5

Annual Plan of Operation Sand River Catchment schedule Jan – June 2014 River Team 1 Team 2 Team 3 Wardens NBAL January February March April May June Westlake River Keysers River Prinskasteel River Prinseskasteel River Spaanchemat Princess Vlei Little Princess Vlei Mocke River Die Oog Paggasvlei Westlake wetlands Zandvlei 6