Spare a thought for our Aussie neighbours. Not only have they been contending with a plague of ravenous mice destroying grain stores, they’re also dealing with poisonous cane toads that have evolved especially long legs, helping them leap their way across the country.
It’s one of the grim tales recounted by Phil Lester, professor in ecology and entomology at the University’s Te Kura Mātauranga Koiora—School of Biological Sciences.
Phil is the author of the recently released Pests and Pestilence: The Management of Invasive Species, Pests and Disease in New Zealand.
Behind the no-nonsense title, the book explores the vast task of tackling pests and diseases at a time when they can spread around the world in days. The COVID-19 pandemic made that crystal clear.
“With new diseases emerging every year, we have some very challenging times ahead of us in managing pests and pathogens. These challenges were a major motivation for writing this book,” Phil says.
The list of intruders we’re already battling is daunting.
“Which is the worst pest will depend on where and who you are. A sheep farmer in Canterbury or Otago will talk about decades of rabbit plagues. They will soon, or already, have wallabies competing with rabbits for pasture and worst-pest status. Many are also seeing wilding pines swallow thousands of hectares.
“People in Northland will talk about the devastation caused by kauri dieback, a relative of the disease that triggered the Irish potato famine. They might also talk about the pandemic strain of myrtle rust, a fungal plant pathogen blown over from Australia, where it has already driven tree species to near extinction.”
History is littered with ill-founded attempts to deal with unwanted invaders. One cautionary tale in Pests and Pestilence is a black comedy involving cats in parachutes and efforts by the World Health Organization to control malaria-carrying mosquitoes in 1950s Malaysia.
“The pesticide DDT was used in villages that had thatched roofs. Mosquitoes were controlled, but caterpillars that were resistant to this pesticide became abundant and ate the roofs,” Phil says.
“Geckos and lizards then ate the caterpillars. These, in turn, were fed upon by the residential cats. Because the pesticide increased in concentration at each step up the food chain, the cats were strongly affected by the pesticide and died.
“Plagues of rats and mice then followed. New cats were brought in by road to most places, but in remote areas, it was more cost-effective to push them out of a plane in a parachute. I’d have loved to have seen it.”
Plagues of rats, rabbits, and wilding pines may make for depressing reading, but Phil remains upbeat.
“There’s much to be positive about. Globally, we’ve entirely eradicated smallpox in humans and rinderpest in cattle. Nationally, New Zealand regularly eradicates unwanted incursions, including those of fruit flies. And by nearly every metric, our COVID-19 response was outstanding.
“Our ‘pandemic era’ future will see many more of the same problems we’re grappling with today, along with new pests and diseases. To limit their potentially devastating effects, we need to learn from and leverage our past successes and our failures.”
Pests and Pestilence: The Management of Invasive Species, Pests and Disease in New Zealand, by Phil Lester, is available from Te Herenga Waka University Press. $40.