Pollinators around the world are in decline and this has important ramifications for human life. Approximately 75% of flowering plants require pollinators to set seed or fruit, and from these plants comes one-third of the world’s food (Xerces, 2011)
Pollinators are primarily insects but birds and bats can also pollinate plants. In Wisconsin, bees, flies, wasps, butterflies, moths, beetles, ants and even hummingbirds readily pollinate both native and non-native plants. Generally, the most effective of these are the bees. Unfortunately, we have seen a significant decline in the population of these amazing creatures. Food plants such as apples, cucumbers, squashes, tomatoes, cherries, raspberries and many others require pollination by insects. Otherwise, they will not bear fruit.
The honeybee (Apis mellifera) is the most common non-native bee use for pollination of crop plants. This bee is easily reared and transported, and a single colony can attain a size of 50,000 or more individuals. The blue orchard bee (Osmia lignaria), also referred to as the mason orchard bee, is a native managed pollinator for orchards. Just 250 of these bees (as opposed to 20,000 honeybees) can pollinate an acre of apple trees (Stewart, 2012).
There are approximately 400 species of bees in Wisconsin. Most are inconspicuous and harmless and many remain unidentified even today. This includes miner bees, mason bees, leafcutter bees, and sweat bees among many others. These pollinators as well as the butterflies, moths and wasps mentioned above may concentrate on only a few native plant species while others are generalists.
Landowners can support native pollinators in three key ways:
Plant Native Plants
By installing a diverse array of native plants, you will be creating an ecosystem that supports many beneficial insects as well as animals and birds. The larger the area and the more diverse the planting in terms of flowering species, the better it will support an equally diverse and healthy population of pollinators. Plants that are especially good for bees include
- wild lupine
- anise hyssop
- purple prairie clover
- mountain mint
- pale purple coneflower
- wild bergamot
- Culver’s root
- butterfly and common milkweed
- native sunflowers
- prairie blazing star
- great blue lobelia
- berry bushes of all kinds
- linden and black cherry trees
Most of the above species are found in prairies and savannas with a few found in woodlands. A comprehensive approach to restoring ecological health will greatly benefit pollinators.
Herbicides do not target insects, birds or animals. However, the long term effects of many herbicides are simply not known. Insecticides, obviously, can harm non-target species. The combination of multiple pesticides in the environment has unknown consequences, but has been blamed for the collapse of honey bee colonies. There are times when pesticides are the only option, but overall they should be used sparingly and in accordance with labeled instructions only when necessary. It may seem counter-intuitive for a company that provides herbicide application services to recommend against their use. However, they are often necessary in the early stages of ecological restoration. In later stages, properly managed prairies, savannas, and woodlands should require little if any pesticide application.
Providing nesting sites
Most bees nest underground, digging their own tunnels or utilizing the burrows of small mammals. Other bee species nest in brush piles, dense clumps of grass, or tree cavities. In other words, a carefully manicured and “clean” landscape is not necessarily the best habitat for pollinators.
Provide natural nesting habitat for bees by leaving dead trees in place when possible. When trimming plants and shrubs, leave stems somewhere on your property as many will have bee larvae in them. Do not mulch all areas of your yard; keep bare areas of ground for use by ground-nesting bees. Practice no-till methods in your vegetable garden (i.e., try not to dig or turn the soil) to allow bee larvae that are underground to develop into adult bees. You also can make or purchase artificial nests that will attract various species of bees such as mason bees, leafcutter bees and yellow-faced bees (Stewart, 2012).
Call Midwest Prairies, LLC to find out how you can help pollinators by restoring Wisconsin’s beautiful and diverse native habitats!
Stewart, Christy (2012). Polinators. University of Wisconsin Cooperative Extension
The Xerces Society (2011). Attracting Native Pollinators, Storey Publishing, LLC