Monarchs are migrating through the St. Louis region now, but residents are seeing fewer of them than ever before. Last year was the second-smallest population ever recorded of eastern migratory monarchs.
“It was a terrible year last year, and based on what we're seeing this summer, they just haven't rebounded,” said Tierra Curry, senior scientist with the Center for Biological Diversity.
Loss of natural habitat along their migration route and increased use of herbicides and pesticides, as well as unpredictable weather caused by climate change, have accounted for an estimated 90% decline in the migrating monarch’s population since the mid-1990s.
Concern for the species’ survival led the Center for Biological Diversity and other environmental organizations to file a petition with the U.S. Fish and Wildlife Service in 2014 to request that the monarch be protected under the Endangered Species Act. That effort is finally coming to fruition: The government agency is expected to decide by December whether monarchs are assigned threatened or endangered status.
“Hopefully that will bring a recovery plan and more resources for the forest in Mexico [where the monarchs winter], more impetus to plant a migratory corridor for them that's safe from pesticides — and has those nectar plants that they need to fly north and fly south — so that we don't lose this amazing migration,” Curry said.
There are several things people in Missouri and Illinois can do to help monarchs during migration. Those measures can also help other insects that are experiencing lower population numbers in recent years — like the beloved lightning bug.
“[Fireflies] have a different habitat and different needs than monarch butterflies, but habitat loss, climate change and chemical use — those same things are a threat to insects everywhere,” said Chris Hartley, manager of living collections, education and facilities at Sophia M. Sachs Butterfly House.
Curry and Hartley joined St. Louis on the Air to share suggestions for how people can help support monarchs, fireflies and other ecologically important insect species in the coming year.
Plant milkweed in the fall for monarch caterpillars to feed on next spring and summer
“Monarch caterpillars only eat milkweed,” said Curry.
Plant fall blooming native perennials, like asters and goldenrods
“Those are [some] of the best plants you can choose for your yard for the monarchs because right when they do erupt into blooms is when the monarchs are passing through our area — when they desperately need nectar from flowers so they can refuel on that long journey,” said Hartley.
Commit to not using herbicides and insecticides
“This comes up a lot when we do classes because people are very familiar with pests on their plants,” said Hartley. “[We] challenge them to observe, and say, ‘If you don't spray those aphids or whatever off your plants, do your plants suffer?’ We know, from caring for our native gardens at the Butterfly House, that they can coexist with the pests that people want to eliminate.”
Leave the leaves
“Firefly babies live in decomposing leaves … sometimes for more than one year, which means they need undisturbed leaf litter for sometimes up to two years,” Hartley said. “Do some raking when the leaves first come down to preserve your grass, and you can use them in your garden beds as a kind of natural mulch. Many organizations recommend putting the leaves there and letting that be the place where they accumulate.”
Curry added that becoming more comfortable with the concept of a “messy” yard is important for many more species, including birds, amphibians and pollinators. “A lot of butterflies overwinter in the leaves. When you rake up your leaves and send them off to the landfill, you're throwing away luna moths or hairstreak butterflies,” she said. “Also, the carbon that would be stored in those leaves in your yard is going to be compressed in the landfill, and landfills are a source of carbon which promotes climate change.”
Get engaged and share what you know
“Talk to your friends and others you know who are also concerned about this,” Hartley said. “You can [also] get involved with the conservation organizations that are actively engaged in doing serious conservation work.”
For more on what’s behind insect population declines — and the efforts to protect species including monarchs and fireflies — listen to St. Louis on the Air on Apple Podcasts, Spotify, or YouTube, or click the play button below.
“St. Louis on the Air” brings you the stories of St. Louis and the people who live, work and create in our region. The show is produced by Ulaa Kuziez, Miya Norfleet, Emily Woodbury, Danny Wicentowski, Elaine Cha and Alex Heuer. Jada Jones is our production assistant. The audio engineer is Aaron Doerr.
