Waikato RiverCare have teamed up with Waikato Regional Council to recruit the Tradescantia Leaf Beetle to help out with a riparian restoration project along the Waikato River. The team at Waikato RiverCare are very excited about this endeavour as it is our first biological control release on a project. In this instance, it is the tradescantia plant that we hope to reduce with these beetles.
Prepping the beetles for release on the bonnet of the vehicle.
Tradescantia or Wondering Jew is a significant riparian weed on the lower Waikato River capable of stopping riparian regeneration by carpeting the river bank in a dense matte of vegetation. Science and observation has proven that the tradescantia leaf beetle is particularly fond of tradescantia and is unlikely to do much, if any, damage to other plants around its release site, making it a safe and ideal biocontrol agent.
Here are some more interesting facts about the tradescantia beetle:
This particular species of beetle is native to South America, however it was brought to New Zealand in 2007 for scientific study.
Before its release in New Zealand, this beetle was not used as a biocontrol agent anywhere in the world.
The main damage to tradescantia plants is caused by the beetles’ larvae which graze the outer layer off the leaves and will eventually skeletonise the plant.
Adult beetles also do their part but chewing holes around the edge of the leaves and will sometimes consume whole leaves.
Although using the tradescantia beetle is not suitable for all of Waikato RiverCare’s sites, there is a huge emphasis in Waikato RiverCare on finding innovative, long-term, and sustainable ways to deal with problem weeds. Waikato RiverCare on its own can only do so much to reduce these pest plants. It requires working together with like-minded agencies toward a common goal to make a big difference. Waikato RiverCare is pleased to work collaboratively with agencies such as the Waikato Regional Council on long-term projects like this, and we look forward to continuing the great work with these agencies.