Brown marmorated stink bug: threat to NZ and identification

We need your help to keep watch for the brown marmorated stink bug. This could attack a wide range of crops and infest homes.

Why brown marmorated stink bugs are a threat to NZ

A brown marmorated stink bug.
A brown marmorated stink bug (Halyomorpha halys).

The brown marmorated stink bug (BMSB) is an agricultural, horticultural, and social pest. It's native to Asia and has spread throughout North America and Europe.

See a map showing the global spread of the bugs

It isn’t established in New Zealand, but this sneaky pest hitchhikes on passengers and imported goods. We’ve caught them at our border many times. We need everyone’s help to keep an eye out for them.

The brown marmorated stink bug feeds on more than 300 plant species. If established in New Zealand it could decimate our fruit and vegetable industries. 

During autumn and winter, thousands of bugs can enter houses to shelter from the cold. When they're disturbed they release a foul-smelling liquid which can make your house hard to live in.

What do brown marmorated stink bugs look like?

Adult BMSB are a brown ‘shield’ shape and about the size of a 10 cent coin.

The easiest way to identify them is from the white bands on their antennae and alternating black and white markings on the abdomen. Its underside is a white/tan colour.

Stink bug eggs are light green, shaped like barrels, and are usually in clusters of 20 to 30.

Brown shield-shaped bug with striped antennae and abdomen

BMSB adult with characteristic markings circled.


BMSBs look similar to some other bugs

There are many other similar-looking species – some of them very common in New Zealand.


Brown marmorated stink bug alongside similar insects to illustrate their size and differences. The brown marmorated stink bug is larger than the species which are currently present in New Zealand.

Some of the species that look the same as brown marmorated stink bugs (second from bottom). Download the poster or fact sheet for more details.


Fact sheet and poster to help you identify BMSB and other similar species

Brown marmorated stink bug fact sheet [PDF, 1.6 MB]

How to identify stink bugs poster  [PDF, 2.7 MB]

What to do if you find a stink bug

If you think you’ve found a brown marmorated stink bug – don't kill it.

  • Catch it.
  • Take a photo.
  • Call us immediately on 0800 80 99 66.

Early detection will give us the best chance of eradicating them before they become established.

How to prevent bringing stink bugs to NZ

If you are travelling from Asia, North America, Chile, or Europe, check your luggage for brown marmorated stink bugs. They can hide in cracks and crevices, so pay extra attention to these.

If you buy anything online or receive mail or parcels from overseas, check them for hitchhikers.

Check your luggage and mail indoors, not outside. This will make it easier to catch any stink bugs you might find.

Video – It would be stink if these got into NZ (30 seconds)

Are brown marmorated stink bugs dangerous?

Brown marmorated stink bugs are not dangerous to humans. They do not bite and are not known to transmit diseases. However, some people may be sensitive to their allergens and smell.

While they may not be dangerous, they do threaten our economy and are a household nuisance.

What MPI is doing about stink bugs

MPI has a number of measures in place to reduce the risk of exotic pests being introduced – including requirements for importers and screening at the border. But there is no such thing as zero risk. It is possible the insect could hitchhike its way into the country undetected.

Brown marmorated stink bug: requirements for importers

MPI also works with the primary industry groups to run public awareness campaigns around brown marmorated stink bugs. This includes digital advertisements, social media, posters, and magazine adverts.

These campaigns help New Zealanders identify brown marmorated stink bugs and know what to do if they find one. To help spread the word, consider printing and displaying a poster at your workplace.

BMSB posters

Brown marmorated stink bug [PDF, 2.6 MB]

How to identify stink bugs [PDF, 2.7 MB]

Countries that have brown marmorated stink bugs

World map showing where brown marmorated stink bugs can be found. Countries where the bugs have invaded are coloured red
Global distribution of brown marmorated stink bugs.

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