Weevils marching onto war
Determined Birdswood resident relieved to have found solution to invasive plant problem
AFTER numerous attempts to clear a local pond of an evasive plant species, Birdswood resident Hannes Pieterse welcomed help from the Agricultural Research Council (ARC) last week to address the problem.
The free-floating plant Salvinia molesta, which does not attach to soil but remains buoyant on the water’s surface, has infested the pond along Nkoninga Street in recent months, blanketing the entire area.
Offering assistance, Angela Bownes from the ARC’s Plant Protection Research Institute delivered 1 000 Salvinia weevils (Cyrtobagous salviniae), a biological control agent against the noxious aquatic plant.
The weevils lay eggs in the leaves, and the larvae burrows through and feeds voraciously on new buds, warping and stunting the plant until it eventually sinks,
Pieterse said the plant problem mushroomed this winter and he tried in vain with his friend Johan van Rooyen to clear them.
‘The plants cause dense mats over the water and blocks out the light, negatively impacting on the ecosystem. It also poses a threat to the marine life.
‘While we know the problem won’t disappear overnight, we are happy to have found a solution.
‘We enjoy fishing at this spot, but this has come to a stop and since there is no activity here, illegal dumping is flourishing too,’ he said.
