Tiny Chilean wasps might be the secret weapon in protecting Tasmania’s apple industry from a destructive pest that can wipe out up to 90% of fruit crops.
Researchers from the Tasmanian Institute of Agriculture (TIA) have released 2,500 parasitic wasps into an orchard in the Huon Valley, hoping the tiny insects will take down one of the industry’s worst enemies – the codling moth.
The wasps, known as Mastrus ridens, are natural predators that specifically target codling moth larvae by laying their eggs inside them.
“The wasp specifically targets codling moth larvae by laying its eggs inside them, reducing the moth population naturally without the need for chemical pesticides,” said TIA Entomologist Dr Jon Finch.
“The wasp will seek out hibernating codling moth caterpillars and lays eggs in the cocoons. When the wasp eggs hatch the wasp larvae feed on the codling moth caterpillars, killing them.”
Codling moth is considered one of the most economically damaging pests to apple growers.
In unmanaged orchards, it can destroy between 50% and 90% of the fruit. It also poses a threat to other crops, including pears, nashi, quinces, stone fruit, walnuts and chestnuts.
Previous attempts to establish the wasps in Tasmania showed initial success but failed to create permanent populations, possibly due to inbreeding in earlier laboratory populations.
“We’re confident that this new importation of the parasitic wasp from our Chilean research partners will establish successfully,” Finch said.
The project will continue over the next two to three years, with plans to release the wasps in other parts of Tasmania affected by codling moth.
Finch assured there are no biosecurity concerns with the imported wasps.
“The species has undergone extensive testing to ensure it does not pose a risk to native insects or animals,” he said.
“The results showed that the wasps only attacked codling moths. Because of this we are very confident that the wasps are safe for the environment.”
The initiative aims to help growers reduce reliance on insecticides while protecting their crops from devastating losses.
