What’s the BUZZ about pollinators and roadsides? Monarch on blazing star

Bumble bee on weed Bumble bee on purple coneflower

Bumble bee on lupine

Did you know…

More than one third of Bumble bees pollinate With 4 acres of open space all human food comes some crops better than lost to development every from plants pollinated honey bees. minute, roadsides are too primarily by bees. important to be neglected Managing roadsides for (U.S. Forest Service 2006). Bee biologists report bees and will a reduction in the create important habitat Roadsides in the U.S. cover abundance and for wildlife, and may more than 10 million acres distribution of once support the pollina tion of land and support common bumble bees. needs of neighboring farms. valuable habitat.

mndnr.gov xerces.org

Photographs by Mike Halverson, MN DNR Manage your roadsides for bees butterflies & Tips for helping bees& butterflies Flowers Traffic and wildlife lant pollination by is an essential ecosystem Pollinator habitat should have a diversity of Movement is fundamental to an ’s life, and Pservice. It is estimated that 60 to 80 percent of the world’s flowers that bloom from early spring until late fall to roads can be barriers to animals, dividing and blocking Enhancing flower diversity 250,000 flowering plants depend on animals—mostly sustain a diverse group of pollinators throughout the movement between habitats. The degree to which • To provide pollinators with continuous blooms, • Plant a range of wildflowers of varying colors —for pollination. Eighty-seven of the world’s growing season. roads are restrictive to animals appears to vary greatly plant seed mixes that include flowers with and shapes. Bees mainly visit blue, white, 124 most commonly cultivated crops are animal- or Research in Kansas found that roadsides planted with between species. differing but overlapping bloom times. yellow, and purple flowers. Butterflies tend to -pollinated forage plants, such as alfalfa and clover, native plants supported more abundant and species-rich Some insects are more vulnerable to traffic mortality • Use local ecotype grasses and wildflowers best visit orange, red, yellow, and purple species. that provide feed for livestock. bee communities than roadsides dominated by non-native than others. That pollinating insects do die as a result of suited to the climate, soil type, and location of the Hoverflies go to flowers of white and yellow. In the United States, the National Research Council grass (brome) and flowers (sweet clover and crownvetch). collisions with passing vehicles is certain, but further intended habitat site. Hummingbirds are drawn to red flowers. The reported noteworthy losses of both managed and wild Butterflies also benefit from the presence of native plants. quantifying the impacts of traffic on pollinators is chal- • For optimal pollinator habitat use a mix of about pollinators (2007). Habitat loss, pesticide use, diseases, Roadsides replanted with native prairie grasses and wild- lenging and studies of the impacts of roads on insects are 50 percent forb seed and 50 percent grass seed. parasites, and the spread of invasive species are the major flowers had significantly more habitat-sensitive butterfly few. causes of pollinator decline. Threats to pollinator commu- species, such as the regal fritillary (Speyeria idalia) and Surprisingly, a roadside inventory of dead butterflies Providing nest sites need nities affect not only pollinators themselves but also Delaware ( logan), than non-native grassy along roads in Illinois found that observed mortality • Nearly 70 percent of bee species nest underground. • Leave some native shrubs along roadside borders natural ecosystems and agricultural productivity. or weedy roadsides. was highest in intermediate levels of traffic, with lowest Some species prefer sunny exposed slopes while to encourage cavity nesting bees. mortality at the highest and lowest levels of traffic. In others prefer level ground. • Butterflies and moths require the correct plants Iowa, research found that more butterflies were killed in • Bees that nest in the ground often prefer to dig for their caterpillars to eat. Monarchs need milk- MN Native Wildflowers with MN Native Wildflowers with for predominately grassy roadsides than in roadsides planted their nests in patches of exposed earth. Native weed and fritillaries need violets. High Pollinator Value Very High Pollinator Value with prairie vegetation, and only 2.8 percent of butterflies bunch grasses such as little bluestem (Schizachyrium • Butterflies, moths, and hover flies often over- Blazing star Liatris Aster Aster observed crossing the road were hit by cars. scoparium) and Indiangrass (Sorghastrum nutans) tend winter in leaf litter or under dead vegetation Compass plant Silphium Bergamot Monarda to grow in dense clumps, leaving small patches of Fireweed Epilobium Culver’s root Veronicastrum bees bare ground exposed. Gentian Gentiana Goldenrod Solidago Joe Pye weed Eupatorium Giant hyssop Agastache Lobelia Lobelia Leadplant Amorpha Reducing the impact of mowing and spraying

Lupine Lupinus Milkweed University • Mow once a year in late autumn, when pollinators • Spot treat invasive plants with a backpack sprayer, Mountain mint Partridge pea Chamaechrista are not flying. Ideally, mowing every 3 to 5 years weed wiper, or similarly well-targeted technique. Obedient plant Physostegia Penstemon Penstemon MI State has the least impact on pollinators and grassland Avoid broadcast spraying or pellet dispersal

MN DNR Purple coneflower Echinacea Prairie clover Dalea birds. because large numbers of larval hostplants or

Wild rose Rosa Spiderwort Tradescantia Cappaert,

Nelson, • Choose a pesticide that is the least toxic and adult forage plants could be destroyed. Sunflower Helianthus David has low residue to control weeds. Spray in the • On farms, overspray and drift of insecticides can by

Carmelita Sites for nesting early morning or evening when pollinators are also affect beneficial pollinators in roadsides. Nearly 70 percent of bee species nest underground, less active. Photograph digging slender tunnels off which they excavate cells for Photograph: The width of the roadside and proximity to traffic does not matter Food requiring pollination: tomatoes, peppers, their eggs. Other bees choose to nest in cavities, chewing to bees. Bumble bee on goldenrod. blueberries, strawberries, cranberries, raspberries, into the pithy center of stems, or clearing out existing apples, melons, sunflowers, pumpkins, plums, holes, in which they create a linear series of partitioned A study of butterfly diversity, mortality, and movement For more information squash, and canola. cells. Some bees need specific nest-building materials such within roadsides concluded that roads could not be con- as mud, resin, or flower petals, which they use to form the sidered barriers to the movement of any butterflies they Web sites Roadsides as habitat partitions. Bumble bees are social bees, and require a small observed. Although between .6 and 7 percent of butterfly • The Xerces Society: Regional information on plants, guidance Though roadsides are not a substitute for wildlands, cavity such as an abandoned mouse nest to house their species were killed by vehicles, the authors considered on providing nest sites, and detailed guidelines for habitat This is a publication of the Minnesota Department of Natural creation and management in a variety of landscapes. they have value as habitat for birds, small mammals, annual colony. Pollinator habitat should include a range those mortalities to be small compared to mortality due Resources, published in cooperation with the Xerces Society. www.xerces.org/pollinator-conservation amphibians, reptiles, ants, and beetles. Roadside habitats of nesting substrates to provide for the differing nesting to natural factors. Such research suggests that the benefit • Minnesota Department of Natural Resource Roadsides for ©2010, State of Minnesota, Department of Natural Resources also provide refuge for pollinators. requirements of pollinators. from roadside native habitat outweighs the hazard from Wildlife Program: Information on how to enhance roadside Department of Natural Resources In environments substantially altered by urbanization passing vehicles. habitat for wildlife, free signs, educational materials. 500 Lafayette Road or agriculture, marginal habitats such as roadsides, Landscape linkages www.mndnr.gov/roadsidesforwildlife St. Paul, MN 55155-4040 drainage ditches, and field edges may be especially Roadsides may serve as corridors for pollinators • Minnesota Department of Transportation: Information 651-296-6157 (Metro Area) important for the conservation of biodiversity. Often the and other wildlife. The linear structure of roadsides about the use of native plants for the state’s roadside 1-888-MINNDNR (646-6367) (MN Toll Free) only seminatural areas remaining within a landscape, these provides continuity within the surrounding landscape. management program.www.dot.state.mn.us mndnr.gov • University of Minnesota Bee Lab: Provides the latest edges provide pollinators with places to forage for food Habitat-sensitive butterflies are much less likely to leave science-based education and outreach on sustainable honey Written by Jennifer Hopwood, The Xerces Society for and nest, while also helping to link fragmented habitats. a roadside planted with native vegetation, suggesting that beekeeping and general bee ecology in Minnesota. Invertebrate Conservation and Carmelita Nelson, Roadsides for for some butterflies, roadside restorations could serve as MN DNR www.extension.umn.edu/Honeybees Wildlife, MN DNR. References and further details are available at protective corridors. Many milkweed (Asclepias) species • Federal Highway Administration: Roadside vegetation www.xerces.org grow readily in roadsides. Monarch butterfly(Danaus management program. Design and illustration by Amy Beyer, Creative Services Unit/ Halverson, plexippus) larvae feed exclusively on milkweed, therefore www.fhwa.dot.gov/environment/vegmgt Office of Communication and Outreach, MN DNR. Mike • National Roadside Vegetation Management Association: Equal opportunity to participate in and benefit from making milkweed essential for monarch reproduction. by Integrated Roadside Vegetation Management guide. programs of the Minnesota Department of Natural Resources is www.dot.state.mn.us/environment/pdf_files/irvm_howto.pdf available to all individuals regardless of race, color, creed, religion, MN DNR Photograph • Monarch Watch: Information about providing habitat for national origin, sex, marital status, public assistance status, age, Pollinators need a succession of blooming flowers. Swallowtail monarch butterflies and monitoring migrations. sexual orientation, disability, or activity on behalf of a local human Nelson, butterfly on vervain. www.monarchwatch.org rights commission. Discrimination inquiries should be sent to • Minnesota Native Wildflower/Grass Producers Association. Minnesota DNR, 500 Lafayette Road, St. Paul, MN 55155-4049; Carmelita For many roadside managers, the biggest concern

by Click on Consumer Directory for a listing of native wildflower or the Equal Opportunity Office, Department of the Interior, about the presence of taller native vegetation along roads is and grass producers in Minnesota. www.mnnwgpa.org Washington, DC 20240. that it will increase the number of accidents involving deer. This document is available in alternative formats to indi- Photograph However, evidence from studies indicates that the presence Books viduals with disabilities by calling 651-296-6157 (Metro Area) or Roadsides with native plants host 35 percent more bee species and of tall vegetation does not increase deer-related collisions. • Harper-Lore, B., and M. Wilson (editors). 2000. Roadside Use 1-888-MINNDNR (MN Toll Free) or Telecommunication Device twice as many bees as roadsides dominated by non‑native plants. Also, because deer often prefer to eat tender new growth of of Native Plants. Washington DC: Island Press. Read online at: for the Deaf/TTY: 651-296-5484 (Metro Area) or 1-800-657-3929 vegetation over tough older growth, allowing native plants www.fhwa.dot.gov/environment/rdsduse/index.htm (Toll Free TTY). Natural history of pollinators to grow without frequent mowing may encourage fewer • Shepherd, M., S. L. Buchmann, M. Vaughan, and S. H. Black. Printed on recycled paper containing 30% post-consumer fiber. 2003. Pollinator Conservation Handbook. Portland: The

Native pollinators have two basic habitat requirements: Munafo Stephen by Photograph deer to browse in roadsides. Xerces Society. Available from: www.xerces.org/books- FSC certified paper and food and somewhere to lay their eggs. Under standing Monarch butterfly larvae feed exclusively on milkweed. pollinator-conservationhandbook/ FSC certified printing. which features in the landscape provide these resources is

essential to maintaining or enhancing habitat for pollinators. Bee photograph by Deborah Rose, MN DNR