A new study shows the southern ladybird has strong potential to be a bio-control agent for fighting the tomato-potato psyllid.
Researchers at Lincoln University have been studying the southern ladybird (Cleobora mellyi) as a bio-control agent for the pest, which has been spreading through the country since 2006, damaging potato and other crops.
Lincoln professor of ecology Steve Wratten said the latest research was done in a glasshouse and shows the southern ladybird's appetite for the pest dented its population for 10 weeks.
He said that was a significant step.
"Biological control of pests by another insect goes back 2000 years. The Chinese did it first," he said.
"But, quite often, we get them to eat the pest but there's no reduction in the pests' numbers, which isn't much good, or there is a reduction in the pests' numbers, but there's no effect on yield, which isn't much good.
"When we add the ladybirds to the potatoes with the pest on, we do actually get a decent crop of potatoes... Taking it right through to a yield effect is very rare, and that's why it's rather exciting that we can do that."