When most people think about pollinators, they envision the honeybee (Apis mellifera) buzzing from flower to flower collecting nectar and pollen.  These non-native bees have become somewhat of a poster child for pollinators but the story of their interaction in the world of insects is not as warm and glowing as the honey they produce.

Honeybee History

Honeybees and humans have had a relationship for thousands of years, with the earliest archaeological evidence dating back as far as 17,000 years ago.  Early colonists brought these busy bees from Europe to the colonies sometime in the 17th century and they have flourished on our content ever since.  Although managed hives have always abounded, they have also escaped captivity and established feral populations across our continent.

There are over 4,000 species of native bees in the United States, yet this one non-native bee has received much of the attention from humans.  It may be argued that all the hubbub is rightfully expressed since these honey producers provide humans with their sweet reward and pollinate agricultural crops along the way.  In fact, these bees have become critical to agricultural production across the US. However, researchers are uncovering a variety of unintended negative consequences to our native bee populations as a result of the honeybee occupation.

Bee Decline and Agriculture

In the last several decades, studies around the globe have reported declines in the diversity and abundance of wild bees.  The drivers of this decline vary by region but can all be related to human-caused impacts. In contrast to wild bees, honeybee populations are increasing as our demand for crop pollination has increased globally. 

I was startled to read a paper from 2016 which mapped populations of wild bees across the US and found that Illinois was one of 11 states experiencing the most serious wild bee decline.  Compounding this problem was the fact that much of the areas with the most decline overlaps with some of the highest agricultural demand for pollination services. So, we are seeing declining native bees in the areas where they are most needed for our food supply.

One trend that has emerged from many of these studies is that wild bees are not able to flourish in the agricultural landscape.  Historically, a major driver in their decline in both the US and globally is conversion of habitat for bees and other wildlife to agricultural areas.  As our areas of agricultural production grow, so are the demands for crop pollination, increasing the managed bee population and negatively impacting wild bees.  It seems to be a compounding problem.

To clarify, the crops which require bee pollination are not the typical row crops we see around central Illinois, such as corn and soybeans.  But, about 35% of our food supply does require the work of pollinating insects, including many of my favorites such as orchard fruits, grapes and strawberries, as well as many vegetables like cucumbers, squash and green beans.

Managed Bees and Pollination Services

Interestingly, not all managed bees are honeybees.  Some species of bumble bee (Bombus terrestris and B. impatiens) are also used for pollination of agricultural crops.  While these bees don’t produce honey we can collect, they are efficient pollinators and can be vital to certain crops, such as tomatoes and blueberries, which require bumblebee’s unique form of pollination, called  buzz pollination. 

Many beekeepers are also interested in protection of pollinators.  So, the mounting evidence against managed bees begs the question, “Does my backyard beehive impact native bees I want to promote”?  With 20,000 to 60,000 bees per hive, honeybees certainly have an impact on wild bees, which are mostly solitary species but they may not pose as serious of threat if our home landscape can provide some diversity of habitat and plants. 

The places where the most serious wild bee declines are being measured are in areas of intense agriculture where honeybees are brought in by the semitruck load for pollination. There is an entire industry of “migratory hives” in the US.  In this practice, hives are moved around to production areas to facilitate pollination as the various crops bloom.

In most of these areas of intense agricultural, there is not much natural habitat and relatively low plant diversity since most of the landscape is occupied by crop production. When millions of honeybees arrive by the truckload, these non-native pollinators simply overwhelm and outcompete our native bees. 

However, research is showing that these areas still need wild bees for pollination.  In areas that do have greater wild bee populations, pollination rates and crop production has been shown to be higher, despite the presence of managed bees.  So, we are finding that even with actively managed bees present, wild bees still play a part and its worth conserving wild bees in production areas for the pollination services they provide.

What Can Gardeners Do?

As gardeners, what can we do to help with this complex issue?  While we cannot supplant our home gardens into fruit production areas around the US, we can plant pollinator supportive gardens which preserve and support our local wild bees.  Simply planting a diverse garden filled with native plants is a great frist step, but if you are interested in learning more about gardening for pollinators or other things you can do to support these all-important insects, please visit pollinators.illinois.edu to get the scoop.

Ryan Pankau is Horticulture Extension Educator with University of Illinois Extension serving Champaign, Ford, Iroquois, and Vermilion Counties.