Brown marmorated stink bug and spotted wing drosophila workshop
In the last week of May, Plant & Food Research hosted a meeting open to Hawke’s Bay apple, wine grape and summerfruit growers on two very important pests that challenge New Zealand’s border biosecurity systems. These pests are the brown marmorated stink bug (BMSB) and spotted wing drosophila (SWD).
Presenters included speakers with international experience in the management of these pests:
Dr Claudio Ioriatti from Italy and Dr David Bellamy from the USA – now based in New Zealand. Along with the international speakers there were also presentations from recognised specialists from PFR and MPI.
The meeting was an important opportunity to learn more about these biosecurity threats not currently present in New Zealand, how they are being managed overseas and what work is being done to minimise the impact these pests may pose on our horticultural industries.
Below is a summary of the main points from the meeting.
Brown marmorated stink bug
MPI readiness for BMSB
- Taking a seasonal approach to pre-border inspection.
- 61 live BMSB have been found this season, often within luggage.
- Two detector dogs currently with more being trained.
- Traps are reported to have an attractant range radius of 124m or about four hectares.
- Chemical control is difficult; only Bifenthrin is available which is a synthetic pyrethroid.
- An operational plan has been developed should a BMSB population be found.
BMSB Council/Biosecurity management
- Probably only one generation per year is likely, may be two in Northland and Tauranga.
- There is a lot of research work in progress or completed that is now being co-ordinated.
- Import permissions have been gained from EPA and MPI for the Samurai parasitic wasp. Note that only MPI can use this tool.
- A highly-dosed insecticide impregnated ghost net can be used as a lure and kill trap or as an exclusion wall/net.
BMSB Chile experience
- Has entered the country with non-organic items.
- They are still attempting to control the population.
- New Zealand and Chile are working together.
- An app is being developed for smartphones to enable reporting of potential sightings.
- Monitoring is possible via pheromone traps and beating traps.
- BMSB produces an aggregation pheromone which could be used, but it is not effective as a ‘lure and kill’ trap. More work is being done.
- More likely cheaper to attempt eradication than pay for long-term management of BMSB.
- As BSBM migrates into orchards, boundaries can be treated with insecticide. Area wide treatments would be preferable.
- Insect proof netting is possible with 80-90% effectiveness.
- Is there a natural or importable parasitoid?
- Considering sterile insect technique (SIT).
- Kamikaze wasp importation being readied if an incursion were to occur.
Spotted wing drosophila
- All production in infected counties is now in cages.
- The impact of this pest on susceptible crops is worse than that for BSBM.
- Spinosad (eg Success) is the only known chemical option. This is registered for summerfruit.
- Eggs are laid in ripe fruit, with up to 13 overlapping generations per year. Population can double every four days.
- Broad host range, different fruit have varying acceptability to SWD. Peach fluff is a barrier. Raspberry seems very desirable.
- Damaged fruit is more accessible to SWD.
- Cherry is susceptible once it starts to colour.
- Care should be taken when changing to a harsher chemical control environment, as that may well be applications every 5-10 days with older style broad spectrum chemistry.
- Monitor and destroy boundary hosts.
- Lure and kill traps are being developed. Current traps can be less attractive than the crop!
- SWD numbers explode once it is established.
- In Chile there is trapping, looking at SIT and biological control.
After the meeting, Richard Mill and Juan Rosales from Summerfruit NZ were invited to participate in a workshop to learn about industry views on the matter and the work industry bodies are doing in preparation for a possible incursion of any of these pests.
More information can be found on the Summerfruit NZ website under Biosecurity.
Download our fact sheet on BMSB here.
Download our fact sheet on SWD here.
Samurai wasp EPA application
The Brown Marmorated Stink Bug (BMSB) is one the biggest biosecurity threats facing New Zealand and is frequently intercepted at our borders. It has the potential to cause significant economic damage to the horticulture industry and to home owners due to its invasive nature.
The BMSB Council made an application to the Environmental Protection Authority (EPA) to release the Samurai wasp to help combat a BMSB incursion should one be found in New Zealand.
Following approval from the EPA, the Samurai wasp (Trissolcus japonicus) can now be used to fight BMSB in the event of an incursion.
The BMSB represents one of the highest risk biosecurity threats to New Zealand. Several industry groups, including Summerfruit NZ, made an application to introduce the Samurai wasp as a biocontrol agent for this pest and a decision on this request was reached late August 2018. According to the EPA’s decision, the Samurai wasp may only be released in New Zealand after a stink bug invasion has been detected, and only at the location of the incursion. This is an extremely important achievement for horticultural industries and will be a very important tool in preparation for the effective and sustainable management of a potential BMSB incursion.
Download the Samurai wasp Q&A here.
Read When twenty-six thousand stink bugs invade your home by Kathryn Schulz, published 12 March 2018, The New Yorker.
Download our fact sheet on BMSB here.
Read MPI's factsheet on BMSB.