The public is being asked to stick by monarch butterflies and help determine the extent of their plight at the hands of a nasty parasite.
Victoria University entomologist Phil Lester is investigating the prevalence of a disease affecting monarch butterflies, caused by a protozoan parasite Ophryocystis elektroscirrha (OE), which leads to deformed wings.
To help find out how widespread the disease is around New Zealand, he's requesting people become citizen scientists and send him samples of spores, collected by pressing a bit of Sellotape against the butterfly's abdomen.
With an unseasonably mild autumn, there is still an abundance of monarchs hatching across the country.
For those who fear that carrying out this procedure will damage the butterfly, Lester says the insect is far more robust than many believe.
“They are actually amazingly tough. They aren’t as damageable as you might imagine them to be," he says.
“You look at the butterfly and think ‘if there’s ever an insect that shouldn't be able to migrate and fly long distances it looks like a monarch butterfly. But in Autumn every year in North America, they will fly 50 to 100km per day to get from Canada to the middle of Mexico. They do it well, they ride the winds, and thermal air masses amazing well.”
He said handling the butterfly wouldn’t harm them if they were held correctly when collecting the spores.
You can go up to a butterfly and grab it gently at the wings and take a little piece of clear Sellotape and you just touch it on their abdomen and from that you’ll get a few scales from the butterfly, but you’ll also pick up any spores.
“So, you put it on a piece of paper you describe the condition of the butterfly, whether it’s male or female and you send it along to me.”
Lester became concerned about the butterfly from observing a significant number of deformities in the insects in his own garden this year.
The scientist, like very many Kiwis who grow swan plants each year to watch the butterflies develop, watched as many of the butterflies struggled to fly and thrive.
“This year we started to see many butterflies that didn’t develop all that well,” he says.
After receiving similar reports from other parts of the country, he decided the beloved insect would be best served by carrying out a survey to find out the extent of the disease.
The parasite had come over from Australia in about 1870.
“It’s probably quite common, but devastating in high numbers,” he said.
The project started in Wellington, but has since expanded to other regions such as Nelson, where a parasitic wasp has also devastated the local population.
He also has advice for those who struggle each year seeing more caterpillars than swan plant leaves in their garden, leaving some smaller caterpillars starving.
“You’ll have to cull, reduce eggs, or otherwise, get more swan plants.”
