Unwanted horticultural pest detected in routine surveillance

08 Jun 2020

Two small populations of an unwanted horticultural pest, the tomato red spider mite (Tetranychus evansi), have been found by Biosecurity New Zealand (the biosecurity arm of the Ministry for Primary Industries) on nightshade weeds at two Auckland locations during routine and follow up surveillance. 

Biosecurity New Zealand is currently carrying out a risk assessment to determine impact and working with horticulture sector representatives on potential next steps. 

There is no way to tell how long the mite has been in New Zealand or how it arrived.  It could have been carried by the wind, arrived on a visitor’s clothing or bags, or hitchhiked on imported products.

As GIA (Government Industry Agreement for biosecurity readiness and response) partners, HortNZ is working closely with Biosecurity New Zealand and will have input to any decisions made. 

The discovery of this mite in New Zealand is considered by MPI’s trade and market access experts as unlikely to have any significant impact on trade in horticultural products.

If you think you have found a tomato red spider mite infestation, please call the Biosecurity New Zealand pest and disease hotline on 0800 80 99 66.

Background information

Tomato red spider mites are the size of a full stop.  They are not insects, but a type of arachnid, relatives of spiders, ticks and scorpions.  There are a few red mite species in New Zealand already. Identification requires an expert.

The tomato red spider mite got its name because it eats tomato plants, is red, and makes silk webbing to protect itself and its eggs, like some spiders do.

The mite doesn't just feed on tomatoes though. Its main hosts are plants in the Solanaceae family and other crops including:

  • crops (tomatoes, potatoes, eggplants, beans and kumara)
  • ornamental plants (roses and orchids)
  • weeds (shepherd's purse, nightshades, cleavers, and fat hen).

For more information, please refer to: https://www.pir.sa.gov.au/__data/assets/pdf_file/0005/299471/Fact_Sheet_-_Tomato_Red_Spider_Mite_-_May_2019_.pdf

https://www.dpi.nsw.gov.au/biosecurity/plant/insect-pests-and-plant-diseases/Tomato-red-spider-mite