KEY POINTSLadybirds can be trained to eat crop-destroying pests, a researcher says.He says if pests are introduced early in a ladybird’s lifecycle, they can recognise them as preferred prey.Scientists are increasingly turning to agrichemical alternatives.
Ladybirds — those tiny, spotted insects— are beloved by many, with some believing their bright colours and polka dot livery bring good luck.
Now, pushing beyond the realm of luck and into agriculture, the small beetle is taking on a new role as a pest-eating assassin, thanks to new research from Murdoch University.
Murdoch University PhD researcher Shovon Chandra Sarkar has successfully trained ladybirds to eat pests, namely, the highly invasive tomato potato psyllid.
Ladybirds are taking on a new role as a pest-eating assassin. Credit: Kevin Sawford
How ladybirds are trained to be pest-eaters
On its own, the tomato psyllid can cause crop yield losses of more than 50 per cent and can also spread a serious bacterial disease called “zebra chip” in potato and tomato plants.
Psyllids also feed on capsicum, chili, goji berry, tamarillo, eggplant and sweet potato crops.
Sarkar found when ladybirds were introduced to psyllids early enough into their life cycle, they could learn to recognise them as their preferred prey.
“I worked on two ladybirds, one is native to Australia and another one introduced in 2002 in Queensland, and now it’s all over in Australia,” he said. “They both are commercially available … other ladybirds we did not try, but maybe we can in the future.”
Both of these types of ladybirds can be bought by farmers online and Sarkar said they can easily be trained to eat pests.
Psyllid is a plant pest that attacks potato, sweet potato, tomato, eggplant, capsicum, chilli and tamarillo, and could significantly threaten vegetable production. Credit: Pia Scanlon
Scientists are increasingly turning to methods such as these as alternatives to agrichemicals, which often have reduced effectiveness as they develop resistance over time.
“One of the challenges that we face here in Australia is we use insecticides and indeed other pesticides in our farming systems,” said Paul Umina, a professor specialising in sustainable agriculture at the University of Melbourne.
“They work very well, but unfortunately sometimes the pests that we’re actually trying to target evolve resistance to those chemicals.
“And so unfortunately that presents a real dilemma for growers and farmers because the chemicals that they were using to achieve pest control may no longer work.
