International students seek out bio-agents

 Horizons environmental officer plants Neil Gallagher says bio-control is a technique used worldwide to restore balance between a weed and the environment by recruiting some of its key natural enemies.

“Pest plants that have been introduced to New Zealand are often not considered a weed in their home country because there are bio-agents there to control them,” he says.

“If it can be determined what these agents are, they can be released in key areas to help fight against weeds such as California thistle, nodding thistle and woolly nightshade. Our team has been active in getting bio-agents established in the Region so were more than happy to host students studying bio-control.”

Horizons staff took student Darwin Hickman from the University of Birmingham and Cecilia Falla-Mata from Guatemala to sites where a number of bio-control beetles, flies, and bugs had been released.

“Our team is really keen to learn everything we can about bio-control. So while assisting Darwin and Cecilia with their visit and helping them collect data, we were also soaking up any new information they could share in order to increase the success of the programme,” says Gallagher.

“We took the students to Pohangina Valley, Ohingaiti, and Utiku and were pleased to find thistle bio-agents had taken a noticeable toll on pasture weeds. In particular the Pohangina site showed at least 50 per cent of thistles were damaged by green thistle beetles and reducing the amount of thistle present.”

Gallagher says New Zealand’s bio-control programme is recognised internationally as being an efficient, safe, and robust system.

“The impressive thing about our programme is that using bio-agents hasn’t impacted negatively on our native plants or agricultural and horticultural crops. This is one of the reasons why students are coming here to see how things work.”