Frequently Asked Questions

Could didymo spread to lakes throughout New Zealand?

Yes. Although didymo prefers a river environment with clear water flowing over stable substrate at depths sufficient for light penetration to drive photosynthesis, blooms have been found in South Island Lakes. Lake Wakatipu, for example, contains visible didymo on some parts of the lake shore.

Is Gum leaf skeletoniser dangerous?

The gum leaf skeletoniser caterpillar is covered with protective spines that sting and may cause irritation. The stiff spines are hollow and contain venom, which can be injected into the human skin upon contact. This often results in local pain (sometimes severe) and welts (swollen patches on the skin) that tend to become itchy. The reaction to gum leaf skeletoniser may last for many days. Note that the spines of dead caterpillars or on shed skin retain their ability to sting.

In case of reaction to gum leaf skeletoniser caterpillars, the following first aid is advisable:

  1. Apply ice packs to the exposed area.
  2. In case of eye contact, wash area thoroughly and seek medical attention.
  3. If ingestion of caterpillar occurs, seek medical attention immediately.
  4. If symptoms develop beyond the immediate area of the sting (e.g. widespread rash, shortness of breath or collapse) call an ambulance straight away.

Biosecurity NZ has prepared fact sheets providing more specific public health information:

For further information, see Derraik JGB. 2006. Erucism in New Zealand: exposure to gum leaf skeletoniser (Uraba lugens) caterpillars in the differential diagnosis of contact dermatitis in the Auckland region. New Zealand Medical Journal 119 (1241) (offsite link to

What are the economic impacts of didymo?
What does Official Government Veterinarian mean?

An official veterinarian means a veterinarian authorised by the Government Veterinary Authority in your country to perform designated official tasks associated with animal health and/or public health.

The pet importer or pet agent must arrange with an Official Government Veterinarian to sign and stamp the import permit application and Veterinary Certificate B.

Why is it taking so long to wipe it out?

Wiping out a pest like the painted apple moth takes time. It took three years to wipe out the white spotted tussock moth after it was discovered in Auckland in 1996. MAF has taken a less aggressive approach to the painted apple moth because it spreads more slowly and it was worth trying alternatives to aerial spraying first. Even so, MAF has successfully contained the painted apple moth to western Auckland and is on track to wipe it out.

How does varroa spread internationally?

There is an international trade in live bees. Queen bees are shipped world-wide, and are believed to be responsible for the spread of the mite to both North and South America, and Africa. New Zealand has not permitted bee imports for many years, but does export live bees.

Why is MAF Biosecurity New Zealand and the Ministry of Health concerned about Asian tiger mosquito?

The Asian Tiger Mosquito is defined as an 'unwanted organism' under the Biosecurity Act 1993. This is because it would be able to breed in New Zealand and could spread some very serious human diseases. These include Dengue fever, Eastern equine encephalitis virus, Japanese encephalitis virus, LaCrosse encephalitis virus, Ross River virus, St Louis encephalitis virus, Western equine encephalitis virus, West Nile virus, and Yellow Fever.

Only one male specimen (males do not transmit viruses) has been found so far, and based on the information obtained to date we believe the risk of contracting one of these diseases through this route is extremely low.

How often do I have to retake Operator training?

Operator training needs to be refreshed every four years.

I have plants in my garden which are on the Accord or being considered for the Accord, will I have to pull them out?

No, you won’t have to pull them out. It is legal to have a plant that is on the Accord list, but it is illegal to sell, propagate or spread it. The agencies and industry groups involved in implementing the Accord work together to make sure that home gardeners receive good information, including the reasons plants have been included on the Accord (ie their environmental impacts).

How often is the National Pest Plant Accord list updated?

Anyone can submit proposals for plants to be added or removed from the Accord list at any time. Proposals will be held by the Ministry for Primary Industries until there are enough to justify a review, unless there is some urgency involved with adding or removing the proposed species.