Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Tackling tutsan with a new biocontrol agent

Manaaki Whenua – Landcare Research reached a key milestone in its war against weeds, releasing a biocontrol agent to tackle the weed tutsan.

Tutsan (Hypericum androsaemum) is thriving in parts of the central North Island and is a threat to farmers’ livelihood. Traditional control methods are expensive, costing an estimated $400 per hectare per year.

Biocontrol offers a cost-effective, environmentally friendly and permanent solution to weed control. Carefully selected biocontrol agents target only weeds, and don’t harm desirable plants or pollute the environment.  They travel to wherever the weed is present and can return again and again to kill off new growth.

In 2014 Hugh Gourlay brought back a moth and a beetle from Georgia, Eurasia, which he bred at Manaaki Whenua’s insect containment facility. On 15 February 2017 the team completed the first public release near Taumarunui, marking the culmination of nearly a decade of hard work.

‘[Farmers] have turned to science for a solution by forming TAG [Tutsan Action Group], a group of farmers who have dipped into their own pockets and joined forces with the likes of us, Manaaki Whenua, Horizons Regional Council and the Sustainable Farming Fund, to come up with a solution,’ Hugh said.

Hugh is optimistic the foliage-feeding beetle (Chrysolina abchasica) and the seed-eating moth (Lathronympha strigana) will eventually be as effective as other biocontrol success stories.