EPA Changes Insecticide Rules To Combat Stink Bug Invasions

The Environmental Protection Authority (EPA) has approved changes to the rules around how a neonicotinoid insecticide, Actara, can be used if the brown marmorated stink bug (BMSB) invades New Zealand.

The Ministry for Primary Industries (MPI) applied to increase the use of Actara from four applications per year up to a maximum of eight in a single area, only in response to a serious BMSB incursion.

There are strict rules around its current use to control insect pests on kiwifruit, pipfruit, and potatoes.

The EPA has put in place additional controls for using the insecticide in a biosecurity response to BMSB. These rules aim to minimise any risks to the environment, particularly to pollinator insects.

"Neonicotinoid insecticides are harmful to bees and other pollinators. For this reason, when Actara is being used during an active biosecurity response to a BMSB incursion, we’ve restricted its use to spot spraying by MPI-approved biosecurity chemical operators," says Dr Shaun Presow, Hazardous Substances Reassessments Manager.

"Before an area can be sprayed, chemical operators must also inform owners, occupiers and iwi, and assess spray sites to identify sensitive areas and organisms."

To further reduce the potential impact on bees, all beehives must be moved from the area for at least three weeks after spraying.

BMSBs are one of the most serious biosecurity threats to New Zealand, with the potential to cost the economy $3.6 billion over 15 years. They can cause crop losses of 90 percent in a wide range of crops, including fruit trees, corn, kiwifruit and avocados.

The stink bugs are in more than 30 countries and have caused billions of dollars in economic losses to global agriculture.

While New Zealand has never had an established population of BMSBs, MPI has recently recorded a marked increase in the number of detections and interceptions at the border.

Most of the insects found have been dead, due to treatment requirements for imported cargo.

Risk analysis by MPI suggests that a BMSB incursion is most likely to occur in an urban area via shipping containers and their contents, new and used vehicles, and machinery.

Grounds for reassessing Actara use were based on significant new information about how effective it is in containing BMSB infestations.

Application to reassess the insecticide Actara | EPA

Editor’s notes:

- A New Zealand Institute of Economic Research (NZIER) report produced in 2017 estimated that if BSMB were to become established in New Zealand it could result in a $3.6 billion drop in GDP by 2038. It predicted horticulture export values could fall by up to $4.2 billion over this period.

- If established, BMSB will settle in houses in warm, confined, dry spaces such as behind and in furniture and in wall and ceiling spaces, and in beds and clothes. Although they are not a direct threat to human health, they are known to have minor irritant effects for some individuals and release a strong and unpleasant odour if disturbed.

- A public consultation on this reassessment was held from 25 October 2022 until 20 January 2023. Eight submissions were received, with five in support and three opposed. A public hearing was also held in March 2023.

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