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Finding milkweed will help save monarch butterflies

By Joy Struthers,
Waterloo Chronicle,
October 13 2017

Milkweed and monarch butterfly photo, courtesy of Ontario Nature

Monarch butterflies can’t survive without milkweed on its migration to and from Canada.

A new project tracking the milkweed plant will allow scientists to find and propagate it, which will help protect the endangered species.

Researchers at Wilfrid Laurier University and the University of Ottawa have launched a new citizen science project so they can collect data about milkweed. The mobile-friendly app, milkweedwatch.ca, allows people to enter information about the plant that researchers can access.

The plants are easy to find in the fall because they have large seed pods that burst open to release hundreds of dark seeds carried on fine white floss. In the spring, they have many intricate flowers.

Robert McLeman, associate professor in geography and environmental studies at Laurier, said milkweed is starting to disappear due to the use of herbicides, expanding farmers’ fields as well as urban sprawl.

“We want to raise awareness among Canadians about how important milkweed is for our ecosystem because of the species that depend on it,” McLeman said.

Over the next couple of weeks, McLeman said the monarchs will migrate to Mexico to reproduce, and those new butterflies will come back here in the spring and reproduce again.

“Their reproduction is completely dependent on milkweed because the female monarch will lay a single egg on a plant – when those lonely eggs hatch, a caterpillar emerges and it eats the milkweed,” McLeman said.

The milkweed itself is slightly toxic, so when eaten by the caterpillar it protects them from other species. The caterpillar will then leave the milkweed plant to hide and metamorphosize.

Jonathan Walgate, president of Waterloo Region Nature, said the arrival of monarch butterflies is one of the most welcoming sights of summer.

“All the more welcome when you know their arrival follows an incredible multi-generational migration all the way from Mexico,” he said.

Walgate called citizen science projects like this milkweed project valuable. He said they generate data that’s hard for researchers to gather by themselves and engage the rest of us, allowing us to gain an appreciation for the natural world around us.

“The more we learn about nature, the more amazing it becomes,” Walgate said.

McLeman said the app is easy to use from your phone or home computer.

“If you’re out for a walk in Waterloo Park and observe milkweed – it’s a few touches on a drop-down menu and you can submit the data. As data accumulates, there will be a map of Canada that you can call up and see where others have logged in milkweed observations,” he said.

The app will tell you the most common species of milkweed in the area – there are really only three, according to McLeman – and you can easily identify them.

Another thing the community can do is leave naturally-occurring milkweed plants alone, or plant more.

“Monarchs love milkweed in the city as much as they do out on the countryside, so people who live in Waterloo, if they want to encourage milkweed in their garden, that would be excellent,” McLeman said.