APP203875: An application to import and release two to control German and common .

December 2020 The application

 Tasman District Council lodged an application with the EPA on 14 September 2020 seeking approval to release Metoecus paradoxus and inanis, as biological control agents for the social , and V. Vulgaris.

 The application was publicly notified:

- 25 support, - 2 neither supported nor opposed, and - 3 opposed the application.

2 The biocontrol agents

Metoecus paradoxus Wasp-nest beetle

Photo by B. Brown Photo by B. Brown

. Target mainly Vespula vulgaris . Target species in the subfamilies Vespinae . Adults short lived and do not feed . Adults feed on . Female lays several hundred eggs . Female lays 300-660 eggs . 1 wasp per beetle . 2 wasp larvae per hoverfly . Lack of host selection from the larvae 3 The target hosts

Vespula vulgaris Vespula germanica Common wasp German wasp

• Accidentally introduced • Widespread and thrive in New Zealand 4 • Highest concentration of social wasp Host specificity

 Host range testing . Volucella inanis does not target  Phylogeny

Order Suborder Infraorder Superfamily

Parasitica (cuckoo wasps and allies) ‘Parasitic wasps’ (potter, paper, and other wasps) Symphyta Sierolomorphoidea Thynnoidea ‘Stinging wasps’ (spider wasps) Scolioidea (scoliid wasps and allies)

Formicoidea () 5 (speciform wasps, bumblebees and ) Host specificity

 Behaviour: social versus solitary . No native social bees or wasps (except native ants) . Valued exotic social species  not targeted  Life cycle . Similar to honeybees and bumblebees . Different to native solitary species . Obstacles for the BCAs:

- Small size - Nest entrance size - No comb Photo by J. W. Early - Sealed chamber 6 Host specificity

 Nesting . Native and valued exotic species do not use plant/wood material . Some bumblebees nest in decaying wood  of the BCAs . Wasp-nest beetle produces a similar chemical signature to V. vulgaris . Hoverfly uses visual and chemical mimicry

V. inanis and M. paradoxus are unlikely to target species outside the family .

7 Risk/Benefits assessment

 We assessed the risks and benefits of bringing the two BCAs into New Zealand, assuming their successful establishment.

 We assessed the risks and benefits to: . the environment, . market economy, . public health, . people and communities, and . Māori and their relationship with the environment.

8 Benefits Environment

 Improve biodiversity:

. Reduce wasp impact: - Wasps collect 12,000 to 75,000 prey/ha/season - No is spared - Remove 90% of the honeydew  Birds  Soil communities

. Reach hidden populations and reduce re-infestations

Photo from Stuff

9 Benefits Environment

 Reduce chemical usage:

. Pesticides . Fertilisers

Photo from DairyNZ

The level of benefits on the environment would be medium to high with the re- emergence of native biodiversity and the decrease of chemical usage.

10 Benefits Economy

 Apiculture: Social Wasps . Limit the cost of honeybee colony loss  $4m per year Increase food Feed on Predation competition honey on bees . Potential reduction in chemical costs  cost $5 per hive/year . Improve productivity Decrease honey More bees to  gain $2.7m per year production protect the hive

Less pollination

11 Benefits Economy

 Agriculture:

. Reduce cost of pollination ($80-$400 per hive)

. Decrease fertiliser usage (avoid a $33.8m cost)

. Decrease clover oversowing (avoid a $28.2m cost)

. Reduce disruption of horticultural/forestry activities

. Reduce crop damages in autumn (grapes, apples, pears)

12 Benefits Economy

 Tourism: . Modify or even cancel outdoor activities.

The level of benefit in the market economy would be low to medium depending on the region and the level of wasp infestation.

13 Benefits Public health

. Reduce the risk of being stung . Reduce the number of traffic accidents

The level of benefits from the successful control of wasps for an anaphylactic person would be significant, whereas, the overall benefits to public health would be low.

People and communities

. Make some tramping tracks more attractive (more birds) . Improve recreational activities (hunting, fishing, camping, tramping, gardening)

The level of benefits on the community would be medium at the local level and low at the national level. 14 Risks Environment

 Increase the use of pesticides for gardeners . Social wasp eliminate other pests

 Replace by a worse pest . Hypothetical

 Impact on non target species: . Host specificity

15 Risks Environment

 Effects on food webs:

. Decrease of wasps . Increase of prey . Add competition for . Increase of pests species

 Hybridisation . No native or valued exotic species in the Metoecus or Volucella

The level of risks on the environment are expected to be negligible to low. 16 Risks Economy

 Decrease pesticide sales  Decrease of revenue for pest control companies

The level of risks on New Zealand’s market economy is assessed to be low.

Public health

 BCAs are harmless

The level of risks on public health from the release of the two BCAs is assessed to be negligible. 17 Summary of our assessment R B n s k s s e e t f I i Public Public health Economy Environment People and community Public health Economy Environment outcomesPotential Negligible Low Conclusion Negligible Negligible Low Low (community) Low Medium - - medium medium - high - low - significant significant (individual) Māori and their relationship with the environment

 Kaupāpa Kura Taiao concluded that the release is likely to benefit the ability and capacity of Māori to maintain their economic, social, and cultural well-being, as well as their culture and traditions with their environment and taonga.

 Te Rūnanga o Ngāi Tahu support the release of V. inanis and M. paradoxus subject to long term monitoring.

19 Minimum standards

 We assessed the release of M. paradoxus and V. inanis against the minimum standards in the HSNO Act. Our assessment concludes that the biocontrol agents meet the minimum standards.

Recommendation Our assessment has found that the benefits of releasing M. paradoxus and V. inanis outweigh any identified risks or costs. We therefore recommend that the application be approved. 20 For more information contact: General enquiries Phone +64 4 916 2426 Fax +64 4 914 0433 [email protected]