Butterflies are likely the most beloved and recognizable group of insects because of their striking wing coloring and patterning. Butterflies are a subset of moths in the order Lepidoptera. Because our North American butterflies are active during the day, and no species is a pest to the average person, they get more respect than their mostly less charismatic moth cousins.
Butterflies have a complete metamorphosis. The life cycle starts as an egg that hatches into a caterpillar. The caterpillar voraciously eats plants to grow and then at a certain stage forms a chrysalis to prepare for its miraculous transformation into an adult butterfly. In much of the United States, the dazzling monarch is the most recognizable of our butterflies and in recent decades has become the poster child for all butterflies.
I’m over 60 years old and have been interested in butterflies since I was a wee one. I remember catching my first butterfly by hand—an orange sulphur—then known as the alfalfa butterfly. Butterflies were abundant when I was a child growing up in northeast Iowa near the banks of the Upper Iowa River. If only I had had a cell phone camera like today’s children, I could prove that the “new normal” of butterfly diversity and abundance is NOT normal. My memories seem like a fantasy now. Across the street from where I grew up in meadows and alfalfa fields I could find olympia marbles; American, bronze, purplish and gray coppers; Milbert’s tortoiseshells; aphrodite fritillaries; and long dash skippers. All of these are now gone, although I did see a gray copper a few years ago, decades after its disappearance. Still-present butterflies are in greatly reduced numbers.
It’s not my brain embellishing fond childhood memories. Local to international research validates my butterfly memories. Dr. Kirk Larsen, biology professor at Luther College in Decorah, Iowa, has had students sample butterflies and compare them to historical documentation by local butterfly expert Bert Porter (see the Porter House Museum in Decorah, Iowa). Bert Porter documented 73 species of butterflies in Winneshiek County in 1908. Dr. Larson’s research in 1998 found 55 species. These numbers dropped to 42 species by 2015. A research study of population trends over the past 21 years of 81 Ohio butterfly species has found a more than two percent drop compounding each year. Some of the best international research has been done in Germany (Josef H. Reichholf), verifying an over 85 percent drop in butterfly and moth abundance in Bavaria.
eyed Susan. Oak and hickory trees are the hosts for the hairstreak butterfly.
If there is one thing to know about butterflies it is this: they are resilient. This is why I encourage gardeners to garden with butterflies in mind. Butterflies can lay hundreds of eggs; many have multiple generations in a single growing season. Compare that to a bird that might have just a few eggs with even fewer species raising multiple broods in a growing season and one can see how home gardens can be a place for numbers to increase. The return of the gray copper to my hometown habitat is a good example of the resilience of Lepidoptera. I try to be optimistic that we can turn this around. Creating better butterfly habitat will also help many other beneficial insects. After plants, beneficial insects are our best building blocks to a healthy web of life.
So, where to begin? Insect declines are mainly attributed to pesticides as well as fertilizers. Fertilizer use and production causes increased carbon dioxide and nitrogen in the atmosphere. So, step one is: drop the fertilizers and pesticides in your landscape and support reduction and capture of carbon dioxide emissions. Why do you need pesticides in your landscape? With butterflies’ amazing metamorphosis, remember that the unseen eggs, caterpillars, or chrysalises easily become non-target casualties, along with the demise of an entire suite of other beneficial insects. 1 I’ve found that having a good diversity of native plants (because with a diversity of native plants comes a diversity of beneficial insects), keeps pests in check all on their own. Additionally, why on Earth would I want to fertilize any plant in my landscape other than those in containers or a veggie garden? Our regionally native plants are efficient and adapted to existing soils and nutrient levels. In the Midwest where I live, we have an abundance of fertile soil. Match plants to your soil conditions and you are good to go—no additives needed.
Our changed atmosphere’s impact on plants is not talked about much. Our current nearly-doubled atmospheric carbon dioxide levels and increased nitrogen deposition that results from extreme rain events have tilted the scale in favor of rank growth of invasive plants as well as aggressive native plants like sumac. Rank growth of cool season grasses and woody species—such as reed canary grass, smooth brome, and orchard grass, and brush and vine species such as gray dogwood and poison ivy—has smothered the plant diversity of landscapes which in turn has diminished the diversity of our insects, including butterflies. So, however we can reduce our own atmospheric inputs will, cumulatively, have a positive impact on wildlife. I’m excited to see a wide variety of electric lawn care equipment at retail outlets. Locally, my electric grid is using much more sustainable solar and wind sources as power plants using mined fossil fuels are phased out. Plugging electric equipment into the local grid is becoming more and more sustainable. When I had a smaller property, I had a reel push mower powered by me, which helped keep me in shape! As I reduce lawn, I plan to return to that mode of trimming the turf.
Step two is: provide habitat for butterflies. Starting with, as I just mentioned, reducing turf. Plant a diversity of mainly native plants adapted to your site conditions and reduce lawn to only what you use. By simply doing this you will inadvertently create the habitat required. Think about this: where do butterflies spend the winter? Butterfly migration is rare. Monarchs migrate, as well as a few other butterfly species. But the bulk of our butterflies spend the winter in a life stage specific to each species. Most of our jewel-like hairstreaks overwinter as eggs while many butterfly species overwinter as caterpillars. Some overwinter in the chrysalis stage (such as all the swallowtails). Even in frigid areas of the United States, several of our butterfly species overwinter as an adult butterfly.
Knowing how butterflies (and moths as well) overwinter, garden “clean up” needs to be reconsidered. What you prune, remove, or clear away may be a home or overwintering habitat for beneficial insects. For example, red-spotted admiral and viceroy caterpillars use the base of a leaf as a sort of sleeping (hibernating!) bag tethered with their silk to a plant. Most caterpillars, such as fritillaries, crescents, satyrs, emperors, and skippers, overwinter snuggled into the leaf litter underneath their host plants. It’s a no-brainer to leave the leaves just like Mother Nature does! (Note: see “soft landings” guides for providing habitat underneath host trees.) Chrysalises attach to all kinds of branches, trunks, and human structures while overwintering adult butterflies often rest in wood piles, under the loose bark of dead trees or branches, and even outbuildings. Again, leave branches and stalks, or examine them carefully if you are removing them before consistent spring warm up.
If you use fire to rejuvenate your landscape, make sure you leave refuge areas of key host plants as none of our butterflies are adapted to survive fire while hibernating (or at any stage where they can’t fly away). I’ve seen too many butterflies eradicated from completely burned landscapes. I’ve even witnessed local wildlife refuge staff over-burn without regard to a fire’s impact on hibernating insect life. Shockingly, landscapes denuded by overpopulations of deer or smothered by invasive plants are showing a similar deleterious effect on butterflies.
Butterflies specifically require their host plants (the plants that their caterpillars are adapted to eat). Learn about the butterflies you have already observed or are likely to observe in your area and plant their host plants. If you plant it, they will come! It’s surprising how far and wide many female butterflies disperse looking for suitable host plants to lay their eggs on. Most do better if you have natural corridors linking your residential habitat to the surrounding habitat—this can be anything from hedgerows, streams and rivers, lakeshores, wooded strips, or meadowlands. It’s part of the thinking behind Home Grown National Park and landscapes using Wild Ones principles.
Adult butterflies also need sustenance. Males especially need to gather minerals required for successful reproduction and they find this in wet mud, sand or gravel, as well as on scat or even rotting fruits. All butterflies have a proboscis to collect sustenance; flower nectar is high on the menu for most, though some butterflies do get their nutrition from scat, sap, or rotting fruit. Plant a variety of plants that bloom from earliest spring through to latest fall to provide nectar for butterflies through the entire season. Many butterflies have favorite flowers to nectar from but some plants (mainly in the mint, carrot, and aster families) provide food for a diverse range of butterflies. Do a bit of local research to ensure top butterfly nectar plants for your region are in your garden.
Cheers to landscaping for butterflies! I’ve gardened for them ever since I became a homeowner. Welcoming them into your living space really does bring great joy. It also creates a more sustainable landscape that welcomes the rest of life to thrive and coexist. I can’t imagine living without a healthy web of life comprised of all types of creatures around me. I’ll never forget a neighbor walking his dog by my house who stopped to thank me because he enjoyed hearing the cacophony of crickets and other singing insects on late summer evenings as he walked past. What I take for granted is sadly not possible in many traditional, usually toxic landscapes. Because of the ecosystem services of our web of all life (everything from providing fresh oxygen, pollination services, pest control/balance of life, pollination services, food and water recycling), if you think you can live without diverse wild things, you should know that you cannot.
1Beneficial insects are casualties of insecticides. While beneficial insects are not targeted for control, pesticides do not differentiate between insect pests and beneficial insects thus both suffer from exposure.
2Monarchs east of the Rocky Mountains migrate to the oyamel fir forests of central
Mexico. Loss of forest habitat from illegal logging and other forest degradation diminish
overwintering habitat and imperil the future of the amazing monarch migration.
Alan Branhagen is a naturalist and plantsman specializing in botany, birds, and
butterflies, and is the author of Timber Press’ The Midwest Native Plant Primer
and Native Plants of the Midwest. Alan has both a bachelor’s and master’s degree in
landscape architecture and is the director of operations at the Minnesota Landscape
Arboretum. All images are courtesy of Alan Branhagen and were photographed in his
front yard.