MIKE MILLER

A recent hike in Great Smoky Mountains National Park (GSMNP) was ablaze with early spring wildflowers. I was amazed at the diversity of insects that busily buzzed among the blooms. Numerous species of butterflies, bees, and hoverflies were all benefiting from the ample diversity of spring flora. GSMNP is one of those special places where huge, unbroken tracts of natural habitat still exist. It is nature at a different scale and magnitude in comparison with our Midwest landscape. The diversity of insect pollinators along these mountain streams attest to the ecological health that is inherent in wilderness.

Closer to home, isolated woodlands and prairies hold small pockets of native habitat. The pollinators are still there, but the diversity and numbers of them are more tenuous. If something were to happen to their small patches of habitat, it could devastate the population. Such is the challenge of small islands of habitat.

The precarious survival of isolated natural areas has brought about a new movement that looks to increase pollinator habitat through “re-wilding” the urban landscape. One of the better-known advocates of this movement is Douglas Tallamy, an entomologist at the University of Delaware. He often points out that the ability for us to preserve large tracts of land, such as GSMNP is a finite proposition in the eastern half of the United States, where 86% of the land is privately owned. Encouraging native plants in our own landscapes will collectively create new expanses of habitat. Insects don’t adhere to property boundaries, so in theory, my backyard habitat and your backyard habitat are connected in the eyes of a bee. There are a few challenges to this as you might expect. If your neighbor is one who cultivates a dense stand of nothing but bluegrass or other non-native species, the collective force of the habitat is somewhat limited.

The other challenge is that people need to understand the importance that native species of plants offer to native species of insects. If the yard is only harboring European weeds, it isn’t providing key species needed by native insects. There is a movement known as “NoMow May” that advocates allowing lawns to bloom with whatever species of plants that happen to be growing there. Locally, you will get a beautiful crop of dandelions. Unfortunately, dandelions don’t provide the right mix of nutrients in its pollen for our native bumblebees. The NoMow May movement originated in the United Kingdom as a method of encouraging people to allow their native meadows to grow to provide habitat for their native species of birds and insects. There, it makes perfect sense since it is tailored for the needs of their native species. So the NoMow May concept might be beneficial to European honeybees that were imported here. We cannot expect this concept to be a cure-all for our native species.

There are no native honeybees in North America. European Honeybees have naturalized themselves by escaping domestic hives. There are however between 400 and 500 species of native bees in the Midwest. About 10 percent of those are colonial, such as the Common Eastern Bumblebee. About 15 percent are what we call kleptoparasitic species that are parasites on other living organisms. The remaining 75 percent of bee species are solitary species. They live out their lifecycle when fertile females create a nest for their offspring. These bees are often specialists, living out their entire lifecycle in association with specialized species of native plants.

A female Spring Beauty Miner Bee gathers pollen from Spring Beauty flowers to take underground.
ANGELA MOREHOUSE

A great example of one of these species specialists is the Spring Beauty Miner Bee (Andrena erigeniae). When I was in GSMNP, they were busy on the profusely blooming Spring Beauty (Claytonia virginica). You can also see them in our local populations of Spring Beauty in woodlands throughout our local parks. This bee’s entire life revolves around this one species of plant. Females will emerge in the spring, and after a brief interlude with a male of the species, they set up housekeeping by constructing a brood tunnel in the soil. This tunnel can be several inches long, with numerous lateral brood chambers. Hence the “miner” moniker to their name. On sunny days when the Spring Beauty blooms, the female will gather the pinkish pollen and carry it back to the tunnel. She creates a pollen packet in a brood chamber and deposits an egg on each packet. At night, she enters her tunnel and blocks the opening to protect her and her brood. Each day she repeats the process, as long as the Spring Beauties are still in bloom, which generally lasts about a week or two.

Once the flowers are finished, so is her short adult life. Her progeny will remain as larvae in the nest through the summer, feeding on the protein rich pollen packets. By late summer or early fall, the larvae will pupate. In late autumn, just before winter sets in, the adults will be fully formed and spend the winter in the brood chamber until next spring. When Spring Beauty once again blooms the following spring, the adults will emerge and start the process all over again.

This is just one of more than 300 species of native solitary bees. Each has a unique niche that is often dependent on specific native plants. If we are going to save our native bees, we must also provide native plants. On an evening walk in my neighborhood of older homes, there is a yard that is full of Spring Beauty. This is a yard that hasn’t seen lawn chemicals since the house was built in the late 1800s. The Spring Beauty Miner Bee is busily collecting pollen and living out its life cycle here. Like Doug Tallamy alludes, we can put native diversity into our landscape. The people who own this yard simply don’t mow it until the Spring Beauty are done blooming.

It is not just bees that are important pollinators. Numerous insect species are dependent on native species of plants. Angella Morehouse is a local field representative for the Illinois Nature Preserves Commission. She graciously provided the photo for this month’s column. She recently wrote a book entitled “Flower Bugs” that dives into the diverse group of insects colloquially called the “True Bugs” or, more properly, Heteroptera. Her book explores the diversity of these insects, their associated flowers, and offers tips for making your backyard habitat a better place for native insects. Info on Angella’s book can be found here at Pollination Press

Angella has shared many tips to gardeners over the years to help improve their backyard habitat. Please see the short list of her top tips on making your backyard a diverse oasis for native insects.