Pollinator’s Who They Are and How to Manage For Them
By Dan Luczynski
In case you haven’t heard pollinators are declining but we can do something to help them. You’re probably asking yourself, “Who or what are pollinator’s and why should I care?” Many species of insects and even some vertebrates are pollinators. Insects include, but are not limited to, honey bees, native bees such as bumble bees, pollen wasps, ants, bee flies, butterflies, moths and beetles. Vertebrates are mainly bats and birds but not limited to these only. However, bees are the number one pollinator in the U.S.
Pollinators visit flowers in their search for food (nectar and pollen). During a flower visit, a pollinator may accidentally brush against the flower’s reproductive parts, unknowingly depositing pollen from a different flower. The plant then uses the pollen to produce a fruit or seed. Many plants cannot reproduce without pollen carried to them by foraging pollinators.
More than 80% of the flowering plants (about 240,000 species) require an insect to move pollen. Approximately 75% of field crops grown worldwide for food, fiber, beverages, condiments, spices, and medicines rely on pollinators. It is estimated that one out of every three to four bites of food and drink we consume come from pollinators. These insect-pollinated crops directly contribute anywhere from $18 to $29 billion to the United States farm economy.
There has been approximately 50% decline in managed honey bee hives since 1950. Beekeepers have been losing about 33% of their hives annually since 2006. To compound this problem, wild honey bee colonies have declined an estimated 70-100% since 1995. Monarch numbers are also on a steady decline – an almost 90% drop in numbers from the 1990’s estimate of the overwintering monarch population in Mexico and an 80% recent decline from the 21 year average in California. It’s difficult to determine the exact cause(s) of decline. Contributing factors may include disease, pathogens, or pests (e.g., Varroa Mite); lack of habitat diversity (e.g., flowers, milkweed); invasive plants; and use of neonicotinoid insecticides.
All of this was a quick overview of pollinators and what they contribute to the world and the value they bring to our environment and our lives. Without out pollinators, plants will not reproduce and we will all be in a world of hurt. So now maybe you are asking what can I do? At least I hope that you are. There are many things that we can do as landowners and as good stewards of the land. It doesn’t matter if you live in a rural or urban setting, you can do your part by planting pollinator friendly wildflowers.
For those of you that have some land that can provide habitat for pollinators, here are a few things to do and/or look for.
Increase the available foraging habitat to include a range of native plants blooming at different times throughout the growing season to provide nectar and pollen throughout the seasons.
Create nesting sites by providing suitable ground conditions or tunnel-filled lumber and appropriate nesting materials. About 70% of native bee species nest in the ground and 30% use tunnels bored into wood. Bumble bees—a small, but very important group of bees for crop pollination— require small cavities in which to fashion their nests.
Reduce the risk to bees from the use of insecticides and herbicides which may impact pollinators or the plants they rely on. Avoid using neonicotinoids. Read the label to determine if products contain imidacloprid, acetamidprid, dinotefuran, clothiandin, and thiamethoxam. Utilize alternative strategies to manage pests, and/or minimize the use of insecticides.
Maybe you have existing habitat such as areas left untilled, woodlots, streambanks, utility easements, conservation areas, and even unused areas around farm lots and buildings. Other things to consider when evaluating or creating habitat is the distance to the foraging plants. Native bees travel from 50 feet up to a half mile. Habitat should be within a half mile of an insect pollinated crop. The bigger the habitat the better, but anything is better than nothing. Gardens are a perfect example of small size pollinator habitat as long as they have the appropriate wildflowers that bloom throughout the growing season.
You can also convert monocultures of grass such as fescue to pollinator habitat. First, eliminate the grass using tillage, chemical burn down, prescribed fire, or heavy clear plastic. The first three options should all happen in late summer to early fall, followed up with a spring planting. The clear plastic should be used in the summer months followed up with a dormant planting in the fall/winter.
The size of your pollinator habitat will likely determine how you will plant the seeds. A large plot may require a no-till drill while a small patch could be disked, culti-packed, broadcast with seed using a carrier such as sand or cat litter, and then culti-packed again. Dormant seeding would take place during freeze/thaw conditions and can be broadcast on top of the ground. Remember to ensure existing sod is treated first to maximize seed-to-soil contact.
Maintenance on these sites will vary based again on the size of the plot. Small plots can be weeded by hand whereas large plots would need some type of mechanical treatment such as spot spraying.
Eventually the site may need to be periodically reseeded, especially if some type of disturbance is applied to the site after a couple of years of establishment.
If this is all new to you or you’re unsure on what to do or how to do it, contact your local NRCS District Conservationist. The USDA/NRCS service center is there to provide you with technical assistance and if eligible may even have financial assistance to establish and manage pollinator habitat. Contact your local service center for more information about USDA Farm Bill Programs for Pollinators.
References
U.S. Department of Agriculture, Natural Resource Conservation Service
Xerces Society Guide: Farming with Native Beneficial Insects and Attracting Native Pollinators
Dan Luczynski is a Resource Management Specialist with the USDA Natural Resources Conservation Service.
Box 1. What are neonicotinoids?
Neonicotinoid insecticides have been adopted because of lower toxicity in mammals than previous insecticides. They are commonly used as seed treatments on about 200 million acres of corn, cotton, wheat, canola, and soybeans combined. Potential risks include:
• Dose accumulates with ongoing exposure
• Long-lived in the environment
• Lethal and sub-lethal effects on beneficial insects (i.e., pollinators, butterflies and invertebrates)
• Water soluble; bind poorly to soil (only 1.6 - 20% of seed coating gets into plants)
• Concerns about potential ground water, surface water & wetland contamination