Environment – Beetle and hoverfly could combat problem wasps

In the peak of summer, our beech forests are thought to host an estimated 10,000 invasive German and common wasps per hectare.

Two new organisms might be enlisted to combat the invading horde. An application to the Environmental Protection Authority (EPA) seeks to release the wasp-nest beetle, Metoecus paradoxus, and a hoverfly, Volucella inanis, in New Zealand as biological control agents to potentially reduce the wasp population.

The application has been submitted by Tasman District Council, on behalf of the Vespula Biocontrol Action Group, which supports research and development into the biological control of the invasive wasps Vespula germanica and V. vulgaris. Manaaki Whenua – Landcare Research conducted the scientific research involved.

The applicant says the wasp population poses a significant threat to primary industries and conservation, by impacting biodiversity and the food supply for native insects, birds and lizards. The wasps also attack beehives, reducing pollination for farmers and the production of honey.

Pesticides, the main control method currently used, have limited effectiveness when infestations are hard to reach or find, the applicant says. They are also expensive, labour-intensive, potentially hazardous to non-target organisms, and treated areas are quickly recolonized by queen wasps from non-treated areas.

The applicant says using the proposed new organisms as biological control agents would be a sustainable option to reach out-of-range wasp populations, and would reduce the damage they cause.

You have until 5.00 pm on 10 November 2020 to have your say.