"The latex sap from broken stems can burn and irritate skin and is toxic to dogs, poultry and cattle," Dr Thomson-Carter says.
"The release of Freudeita cf cupripennis is intended to control and eradicate a pest plant species that prompts more enquiries to Auckland Regional Council than any other.
"Research reveals that moth plant is widespread.
"It has been found at the summit of Rangitoto Island, 260 metres above sea level, has spread to isolated coastal areas such as Ruapuke Beach, southwest of Raglan, and is also present in the South Island at Banks Peninsula," Dr Thomson-Carter says.
Three thousand DoC staff hours have been spent to control this invasive weed between 2014 and 2019.
Root-feeding biological control agents have a successful track record.
The beetle is likely to attack only plants within the sub-tribe Oxypetalinae.
Swan plant (Gomphocarpus) and milkweed (Asclepias) were not palatable to adult beetles and did not support larval development.
Few native birds are expected to be capable of feeding on the insect.