Habitat Management for West Virginia's Pollinators
Who are West Virginia’s Pollinators?
West Virginia’s insect pollinators include bees, butterflies and moths with some wasps, flies, beetles and ants. While the non-native, European honey bee (the bee managed by beekeepers) is the most important crop pollinator in the United States, native bees, such as bumble bees, mining bees, carpenter bees, long-horned bees, squash bees and sweat bees, also are critical. These native bees are often specialized for foraging on the flowers of native plant species and specific crops resulting in more efficient and effective pollination and in the production of larger, more abundant fruit.
Why Protect Pollinators?
Since more than 35% of the food crops we eat and three-fourths of the world’s flowering plants require animal pollination to reproduce, without pollinators, our landscape and our diets would be far less diverse and our food prices would skyrocket. Insect pollination also accounts for $18 billion to $27 billion in crop production value in the United States annually.
Our pollinators have declined due to habitat loss, use of pesticides, invasive species, climate change, pathogens and diseases, among other factors. Managed colonies of European honey bees have suffered a 50% decline in recent decades, with approximately one in three hives being lost each winter between 2006 and 2014. At least 25% of our North American bumble bee species, including West Virginia's federally-listed rusty-patched bumble bee, are at risk of extinction. With them could go our tomatoes, peppers, cranberries, blueberries and other crops that rely on buzz pollination (a specialized pollination behavior honey bees cannot perform) for optimum fruit set. More than 17% of our North American butterflies also face extinction, with our beloved state butterfly, the monarch, in particular peril since its populations have plummeted by 80% to 90% in the last two decades.
When their habitat needs are met, the nearly 4,000 species of wild native bees in North America make significant contributions to crop pollination on farms. In some cases studied, such as squash production in New Jersey, native bees provided 100% of the necessary pollination. As securing hives of European honey bees for crop pollination becomes more difficult and expensive, protecting and restoring habitat for native bees becomes even more important. This habitat, full of diverse nectar resources and free from pesticides, is also critical for helping to support local beehives, native butterflies and a myriad of beneficial insects.
While the specific habitat needs of the many species of West Virginia pollinators depend on the species’ life history and the time of year, there are basic habitat requirements all insect pollinators share. Pollinators need protection from pesticides, diverse flowering plants that provide pollen and nectar resources for adult pollinators throughout the growing season, and habitat for nesting, larval development and overwintering.
How Can West Virginians Help Pollinators?
Reduce or Eliminate Pesticide Use
Pesticides are one of the major threats to healthy pollinator populations. Insecticides can kill pollinators outright and are especially detrimental if they are applied preventively before a pest is even present. Systemic insecticides, like neonicitinoids, also can have negative impacts on pollinators since their residues may be found in nectar and pollen. Herbicides, which can be a useful tool for eliminating invasive plants and grasses that outcompete native wildflowers, can also destroy the nesting, larval and overwintering habitats pollinators need, as well as native plants that provide excellent nectar and pollen resources.
Instead of turning first to chemicals to control pest plants and insects, land managers should consider integrated pest management. IPM is a strategy that employs three phases to address pest problems: use cultural practices to prevent pests; take the time to monitor and identify any pests that occur; and use pest controls (chemical or non) only when a certain threshold of pest activity is reached.
When, after exhausting other options, pesticides are used, follow the label guidelines closely and use application methods that minimize damage to pollinator populations. Those can include spraying at night, never spraying when plants are blooming or on windy days, mowing or removing flowering weeds from fields before spraying crops to remove the pollinator attractants, and spraying chemicals that are specific to the pest instead of using broad-spectrum pesticides. Whenever pests become an issue, always ask your local WVU Extension Service agent for the approach that will be least harmful to pollinators.
Provide Foraging Habitat for Adult Pollinators
One of the most attractive and effective ways to increase pollinator populations on your property is to nurture a variety of flowering plants that will provide nectar and pollen to adult pollinators. To best help pollinators, a landscape of diverse native plants is optimal and should range in height, flower shape and flower color with successive blooms that provide forage throughout the growing season.
Consider your space, your existing plants and the potential flowering plants in your seed bank when you develop your pollinator areas. Realize that pollinator foraging habitat can be a small, well-planned butterfly garden, a large bee meadow filled with native wildflowers, a fencerow with various layers of flowering trees, shrubs and forbs, or even pollinator-friendly field borders and cover-crops. Simply changing your mowing habits to allow marginal lands, fencerows and ditches to revert to some native vegetation, such as asters, goldenrods and milkweeds, will dramatically improve the nectar resources on your property and promote pollinators as well as other beneficial insects that make up a healthy landscape.
Create or Enhance Habitat for Pollinator Nesting, Larval Development and Overwintering
While the various species of pollinators have dramatically different life histories, providing nesting, egg-laying, pupating and overwintering habitats for most species is not a difficult task if you always keep diversity in mind. Provide a species-rich floral foraging zone and keep adjacent areas unmanicured to provide the refuge most West Virginia pollinators require to complete their life cycle and overwinter safely.
The majority (about 70%) of our native bees are solitary ground-nesters. These species need bare patches of undisturbed sandy or loamy soil in which to excavate their nests. Avoid mulching and tilling these areas to prevent nest disturbance. Additionally, since landscape cloth and plastic sheeting prevent ground nesting, avoiding these weed barriers will help promote the largest number of our native bees.
About 30% of our native bees are solitary cavity or tunnel-nesters, using pithy stems of vegetation or insect tunnels under tree bark to create their nests.
Allow old snags and downed trees to remain on your landscape and refrain from “cleaning up” your marginal lands and fencerows. Instead leave pithy stems, such as teasels, reeds and blackberry, that tunnel-nesting bees can use for egg-laying sites. All solitary bees rarely sting, if ever. Just refrain from physical contact to coexist happily with them.
Bumble bees are a critical type of native bee for crop production, largely due to their ability to buzz-pollinate important West Virginia crops, such as tomatoes and blueberries. Bumble bees use old rodent burrows, clumps of bunch grasses, brush and rock piles as sites for their single-year colony nests. These types of habitats also are valuable to many other beneficial insects and pollinators as sheltering and overwintering sites.
Most of our native butterflies, which change from caterpillars to adult butterflies through a process known as metamorphosis, require host plant species for their caterpillars to eat before changing into butterflies. Planting and protecting these plant species will provide critical habitat for these butterflies and provide nectar resources for other pollinators when these plants are in bloom. Since monarch butterflies are in danger of extinction, planting, promoting and allowing various species of milkweed ( Asclepias spp), the monarch’s only host plant, on your landscape could mean the difference in the survival of this species.
To provide pollinator habitat, begin by evaluating the current habitat. Reduce or stop mowing your landscape for several weeks or months, then note what blooms appear and where you see pollinators. This will change throughout the year as native flowers have varying bloom periods. You can pay attention to the flowers you see in marginal areas and along fencerows, as these can be good indicators of what plants may be in your soil’s seed bank. Also watch for bee-nesting sites and for butterfly host plants.
Once you have identified pollinator habitat on your property, take steps to protect what already exists. Refrain from mowing nectar plants and removing nesting sites for tunnel-nesting bees, as well as tilling or disturbing sites where ground-nesting bees are present. Simply deciding that you prefer natural-looking pollinator habitat to a neatly-mowed fencerow or roadside ditch can dramatically improve your landscape for pollinators.
If you determine you’d like to add to the diversity of nectar plants on your property, you then need to decide if you want to add a pollinator meadow, a small garden, plant a nectar-rich hedgerow or add to nectar diversity by adding flowering trees and shrubs (an option often suitable to the slopes of West Virginia). These and other approaches will all require some imagination and planning to maximize your benefits and minimize the effort and maintenance required. Contact your local WVU Extension Service, WVDNR or NRCS office for advice on planning a pollinator planting.
Quick Facts About Insect Pollinators
- Native bees, such as the blue orchard bee ( Osmia lignaria) have been shown to be the most efficient pollinators of certain crops, like apples, which require only 250 female blue orchard bees per acre to achieve effective pollination, but would need 15,000 to 20,000 honey bees to accomplish the same feat.
- A monarch caterpillar munches on milkweed, the only host plant for eggs and larvae of our state butterfly. From the time it hatches until it turns into a chrysalis, this caterpillar will grow up to 2,000 times its original size.
- Tunnel-nesting bees, such as mason and leafcutter bees, can benefit from artificial nesting structures like this tube bundle.
- Pollinator meadows can provide an array of pollen and nectar options for pollinators if established and maintained properly.
This content was developed in partnership with the West Virginia Division of Natural Resources, the USDA Natural Resources Conservation Service and the Appalachian Hardwood Center at WVU.
Author: Sheldon Owen, WVU Extension Wildlife Specialist
Last Reviewed: June 2021