Beetle to control the weed moth plant

30 May 2019

The moth plant beetle, an organism new to New Zealand, can now be used in the fight to control moth plant.

In mid-May the Environmental Protection Authority (EPA) approved an application by Waikato Regional Council to import the beetle. Read more about the EPA decision and process here.

Moth plant is a problem weed on many kiwifruit orchards, especially from the Bay of Plenty north. It infests shelter belts, slows down hedge trimmers and is a major host of Passionvine hopper.

The moth plant beetle feeds on moth plant foliage but this damage is not usually significant. Eggs are laid on or in the ground around the base of the stem and hatching larvae burrow down to feed on moth plant roots. The beetle is specific to moth plant and will not attack kiwifruit or any other orchard plants.

This approved biocontrol agent will hopefully assist in the long-term control of moth plant – in the meantime orchardists should maintain removal programmes, especially as it is a weed often smothered with Passionvine hopper. It is a poisonous plant, the sap may cause severe dermatitis through any skin contact, so PPE must be worn when removing this plant.

The most effective control method is to dig plants out of the shelter belt, being careful to remove all of the roots. Alternatively, the plant can be killed with herbicide: cut the vine to within 20cm of ground level and carefully apply one-part glyphosate to five parts water, plus a sticker such as Pulse, to the vine base.