Here's why monarch butterflies are thriving in Manitoba

Some self-proclaimed Manitoba “monarch butterfly enthusiasts” are working hard this summer to make sure the endangered species remains in full flight for years to come.

Sara McPhail has been raising monarchs from egg to adult for the last four years. While she has already released more than 100 butterflies this year, McPhail said the season’s been slower than she’s used to.

“This year, I know the amount of overwintering monarchs in Mexico was down significantly from last year, there was only about 0.9 hectares of space that was occupied,” McPhail said.

“I think along their migration, depending on weather patterns and the amount of milkweed available, it directly affects the number of monarchs that we get here in Manitoba.”

To help increase their chances of survival, McPhail collects eggs from milkweed plants she finds in ditches and grows in her backyard. She set up an enclosure with mesh netting where she cares for the caterpillars until it’s time for them to pupate, before they’re ready to be released.

She said the process typically takes about a month.

“When I learned that you could raise them and help their population and just help keep them safe from predators, it was an absolute no brainer,” McPhail said. “I was all in from day one.”

The practice is soaring in popularity across the province, with many homeowners, like Louise Woods, making a hobby out of it.

Woods lives near Brandon, Man., but spends time in Pelican Lake, where she helps raise monarchs at all stages.

She said it’s really crucial to collect the eggs to prevent the bugs from being infected.

“Once the caterpillars get just a few days old, a fly will lay eggs on them and it’s a parasite,” Woods said.

But parasites are just one of the issues the insects face. Their milkweed habitats are also often mowed down while caterpillars are still growing or dusted in pesticides.

“If we kill off milkweed, there will be no more monarchs in Manitoba,” Woods emphasized.

In a statement to CTV News, the City of Winnipeg said it doesn’t spray milkweed and tries to avoid the plant whenever possible.

According to the provincial government, while rural municipalities may use herbicides to kill off invasive weeds, the spray itself isn’t harmful to the butterflies.

“Common milkweed are very resilient,” said Jason Gibbs, an associate professor in the entomology department at the University of Manitoba. “So some sort of disturbance … they can rebound from that, and those disturbed milkweeds might actually be attractive … for the monarchs.”

Gibbs said it can also disturb predators.

In the meantime, McPhail said she hopes that more monarchs make their mark on Manitoba.