Summer is here, flowers are blooming and insect pollinators are abuzz at Stone Lab and around Ohio
What are pollinators, why are they important and what can Ohioans do to help them thrive amid widespread declines?
Ohio is home to about a dozen species of bumblebees, social insects that live in colonies. (photo: U.S. Fish and Wildlife Service Midwest)
Pollinators are bees, butterflies or any kind of animal that helps plants reproduce by transferring pollen. Moths, beetles, wasps, flies and even some species of birds, bats and other small mammals can all pollinate plants.
A bee might visit thousands of flowers in one day, collecting food and inadvertently transporting pollen that gets stuck on its legs. When pollen grains move from the male part of a flower (the anther) to the female part of the flower (the stigma), pollination happens. This allows the plant to produce fruit and seeds.
Ohio is home to a diverse array of pollinating bees, including the managed western honeybee and approximately 500 species of native bees. These bees can be social — such as bumblebees living in colonies — or solitary, nesting underground or in tree cavities.
One popular pollinator travels through the state each summer. Each year, across four generations, monarch butterflies migrate over 3,000 miles from overwintering sites in central Mexico to the northeastern U.S. and Canada and back. While breeding in Ohio, the black and orange butterflies rely on milkweed as host plants. Monarch caterpillars will only eat milkweed plants, and in turn females will only lay eggs on the plants.
Many monarch butterflies migrate along Lake Erie’s shoreline and even make the long trek across it. During their fall migration back to Mexico, the butterflies will cross the lake and roost on islands in Lake Erie’s western basin to rest before continuing their journey.
A group of monarch butterflies — called a “roost” — rest near Stone Lab after traveling across Lake Erie in the fall.
Stone Laboratory has a certified monarch waystation located at the South Bass Island Lighthouse, and staff will tag monarchs as they migrate through the area. Last year, a monarch that was tagged at the waystation in September was later recovered in Sierra Chincua, Mexico — 1,837 miles away.
Why do pollinators matter? For one, they’re critical to the health of ecosystems. An estimated 87.5% of the world’s flowering plants, over 300,000 species, rely on pollinating animals to survive.
A two-spotted bumblebee pollinates a purple coneflower. (photo: U.S. Fish and Wildlife Service Midwest)
Meanwhile, one third of food crops around the world depend on pollinators, including countless fruits, vegetables and nuts. Some scientists estimate that one out of every three bites of food we eat exists because of pollinators. For example, tomato plants rely on bumblebees for pollination.
Unfortunately, pollinators are in peril. Populations of bees, butterflies and other insects have experienced declines in recent decades.. For example, eastern monarch butterfly populations declined by 80% in the past 20 years. Loss of breeding habitat, overuse of pesticide, overwintering site degradation, disease and climate change all contribute to these losses.
Thankfully, anyone can take steps to help pollinators. Whether it’s one plant in your yard or acres of habitat on farmland, anything helps.
“With pollinators and monarchs both in decline, we want to show that Stone Lab and Ohioans can make a difference,” said Susan Bixler, education and outreach associate at Stone Lab. “Just as we have planted a monarch waystation at Stone Lab, we also want to engage and empower residents to do the same.”
Monarch butterflies typically arrive in Ohio in mid-to-late June. Depending on the weather, the butterflies might have two to four different broods in the state.
Plant native plants, which provide abundant nectar and pollen for beneficial insects. Choose a variety of flowers ¬— different colors, shapes and sizes — that bloom across spring, summer and fall to attract many species and create a continuous food supply. Grouping plants together in clusters also makes them easier for pollinators to find.
In addition, Ohio is home to 13 native species of milkweed that monarchs use, such as common milkweed, butterfly-weed and swamp milkweed. Planting milkweed, plus other native flowers for nectar sources, will strongly benefit monarch butterflies.
It’s not all about flowers, too. Native grasses, branch piles, dead trees, bare soil and water sources all serve as important habitat features for various pollinators. Finally, consider reducing or eliminating pesticide use and helping to raise awareness.
“Everyone can help protect pollinators by planting pollinator friendly plants, providing habitat and being more aware of the adverse and unintended effects of pesticides of the pollinators we are trying to protect,” Bixler said.
For more information about Ohio native plants, visit plantpath.osu.edu/nativeplants.