New Zealand is on high alert for an invasion of brown marmorated stink bugs, a pest that is widely regarded as the greatest biosecurity risk that nation faces.
European farmers already reported large-scale damage. Italy has been hit particularly hard during its summer season, with damage to fruit crops including apples, pears, kiwifruit, grapes and stone fruit exceeding €400 million (NZ$675 million), leading to some farmers considering walking off their land for good.
New Zealand scientists have been working alongside Italian colleagues to help develop new methods for monitoring and controlling the bugs. Like New Zealand, Italy has a wide range of produce, often grown in relatively small, mixed plots. This system works in the stinkbug's favour, as they can easily move from crop to crop.
"There tends to be mixed cropping systems where you might have kiwifruit in one field and then pears in another," says Dr Catherine Duthie of the Ministry for Primary Industries (MPI). "So that provides a really good opportunity for bugs to move around and feed on their preferred fruit."
The brown marmorated stinkbug originates from Asia, where its numbers are kept in check by predators such as the samurai wasp, which lays its eggs inside the eggs of the stinkbug. About the same size as an ant, and with none of the annoying habits of the common wasps that dominate our summer, the samurai wasp has approval for release in New Zealand if a stinkbug invasion should occur.