One of the biggest factors affecting pollinators is habitat loss. A good example of the impact of this is what happens to the Monarch butterfly whose sole source of food for its larval stage is milkweed. Monoculture cropping, GMO crops which encourage intensive herbicide use within and around crop fields, and expansion of corn plantings for ethanol production have significantly reduced the number of milkweed plants. The loss of the plants has resulted in a precipitous decline in population of this iconic and once abundant butterfly. Milkweed flowers are also great nectar source for bees too, so the loss of milkweed has impacted more than just the Monarch.
Monocultures have affected honeybees and many of the native bees similarly. Once one crop is done blooming, there’s nothing else for them to feed on. As a result, some species of bumblebees that were once abundant are now threatened. Nesting sites and overwintering sites for hundreds of different native bees have also been on the decline as suburbs expand into wildflower meadows, woodlots and wetlands converting diverse habitats into monoculture lawns.
Bees Love Good Pasture Management and Cover Crops
The good news is that the way you manage your pastures can provide pollinators with the habitat they need to thrive, and to help us survive. In addition to planting pollinator friendly plants or letting native plants grow around your yard, barns and ditches, managing cover crops and pastures can be a great way to enhance pollinators on your farm.
In a recent SARE (Sustainable Agriculture Research and Education) grant, we found that buckwheat and Phacelia tanacetifolia (lacy phacelia) both provided excellent weed suppression, did not act as weeds the following year, and provided pollinator-friendly plants for honeybees and bumblebees. Other cover crops and forage plants such as clovers, mustards, alfalfa, and birdsfoot trefoil are great pollinator resources. As an example, frost seeding clovers into your existing pastures will not only improve your forage quality but will help the bees. Creating specifically designed bee pastures could be a great way to enhance pollinator and beneficial insects on your farm. These are designed especially to provide floral resources during the season when there is a lack. The timing would vary depending on geographical location, but in Vermont, it is typically mid-summer before the goldenrod has bloomed. This was when we keep strips of clover in many of our fields and time cover crops to bloom.
For the past two years, we have also had warm autumns in Vermont and noticed that late September (after goldenrod and aster have gone by) has become floral resource limited. We put in late buckwheat and phacelia plantings as well as planted large patches of Maximillian sunflower (a late bloomer) and were delighted at the numbers of honeybees, bumblebees and many other pollinators that foraged on these flowers when not much else was available.
Finally, for landowners mowing fields or meadows just to keep successional trees and shrubs from getting established, the best time to mow is in the fall after the Monarch caterpillars have turned to butterflies and the goldenrod and asters have gone by. The honeybees, native bees and butterflies will thank you for it.
Another major factor affecting our pollinator populations is the use of pesticides. Hopefully, grass farmers aren’t using pesticides, but if you grow corn, soybeans or canola, then chances are your seeds are treated with neonicotinoids (neonics for short). These are systemic pesticides that get into all parts of the plant including pollen and nectar. Treated seed dust is also confused for pollen by bees and gets mixed in with the pollen fed to the bee larvae. Some communities in the US and Canada and countries in the EU have banned or restricted neonic use because of their impacts on pollinators. We should all think about our lawn care and food choices too if we want to support pollinators.
Help the Bees Help Us
Even if your focus is grass-fed livestock you still need the tiny pollinators to pollinate and propagate your clovers and forbs. Also, one third of the food we eat requires insect pollinators and is considered threatened by their loss. Pollinators also play a crucial ecological role in our local and global environment. By improving conditions so that our pollinators thrive, we are taking better care of the planet and ourselves.