Pea weevils can damage crops
The pea weevil (Bruchus pisorum) is a small insect that can damage growing peas. It is an unwanted organism under the Biosecurity Act 1993.
If they became established, they could have a serious effect on our pea growing and processing industries. Pea weevils were found in the Wairarapa area of the lower North Island between 2016 and 2017.
Pea plants and pea straw were banned to remove the pea weevil's food source and cause them to die out. The ban was lifted on 17 February 2020 and the response was formally closed in October 2021.
What pea weevils look like
Pea weevils are small (4mm to 4.5mm long) insects, brownish-grey in colour with white flecks. The end of their abdomen has a white marking that looks a bit like an airplane.
They lay between 1 and 12 long, yellow eggs on the outside of pea pods. Eggs hatch in 1 to 3 weeks and the larvae then burrow into the pea.
Pea weevil larvae are up to 6mm long, white to cream, with a brown head.
Risk to New Zealand from pea weevils
Pea weevils could have a serious effect on our export pea seed markets and the processed green pea industry if they ever became established in New Zealand.
Weevils spread by flying from one site to another, and can also be moved in infected pea seed, straw, or dirty farm machinery.
Pea weevil larvae feed on young peas, damaging crops. Larvae tunnel inside the peas, eating the contents as they mature. Pea weevils only affect green ripening peas, not dry peas, but the adults can remain hidden in grain for up to 2 years. Affected green peas can become foul and unfit to eat. Seed might still germinate but the seedlings are often weak and prone to disease.
What we did when pea weevils were found
When pea weevils were discovered, Biosecurity New Zealand imposed legal controls in the form of a Controlled Area Notice. The notice made it illegal to move any peas or pea material (like pea straw) out of a defined area of the Wairarapa. In addition, there was a ban on growing any peas in the controlled area. This effectively starved the pea weevils of their sole food source and caused the population to die out.
To ensure the eradication was complete, Biosecurity New Zealand carried out surveillance by planting trap crops to attract any remaining weevils. Once 2 consecutive seasons had passed with no detection of pea weevils, eradication was able to be declared.
Who to contact
If you believe you have found pea weevils, call our pests and diseases hotline on 0800 80 99 66.
If you have questions about pea weevils:
- email info@mpi.govt.nz
- call 0800 80 99 66.
