This issue briefing comes to us from Daria Syskine and Bethany Bronkema, two of the four student researchers from Swarthmore who spent 10 weeks with POP this spring researching and developing resources for our School Orchard Program on addressing threatened pollinator habitat.  This is an issue vital to POP, as nearly all of our fruit crops are dependent on insect allies like bees for successful pollination and fruit production.  

Think “bee,” and you’ll probably picture the familiar European honeybee (Apis mellifera) – small, with gold and black bands across its belly. But before the European honeybee was introduced to North America, there were already 4,000 species of bees on this continent.

Pennsylvania is home to 300 native varieties of bees – including: large, fuzzy bumblebees (Bombus spp.) that love crops that honeybees can’t pollinate — blueberries, tomatoes, orchard crops; tiny, solitary iridescent sweat bees (Halictus spp.) that often snack on alfalfa, onion, and cane berry flowers; leafcutter bees (Megachile spp.); squash bees (Peponapis pruinosa); mason bees (Osmia spp.); mining bees (Andrena spp.); and more!

Although each of these varieties of bees have different life cycles and habitat needs – bumblebees, for example, live in small, perennial colonies with a queen and worker bees, while other types of bees are mostly solitary – they all rely on flower nectar and pollen for their food. 

From top to bottom: a bumblebee, squash bee, and a sweat bee. Photos credit: PSU Extension

Since native bees tend to specialize in a few plants, they help preserve local biodiversity while also filling in the gaps left by honeybee pollination. In fact, one study showed that on farms in Pennsylvania and New Jersey, wild bees provided most of the pollination for the studied crops; and unlike rented honeybee colonies, their services are free for farmers!

Unfortunately, native bees like their honeybee counterparts are under siege, and are experiencing sizable declines in their populations. Notably, the US Fish and Wildlife Service recently placed the rusty-patched bumblebee on their endangered list.

One major threat to bees is the overuse of pesticides, especially neonicotinoids, a class of neuro-active insecticides that disrupts the central nervous systems of insects and is commonly found being used in seed coatings (especially with corn, soy), ornamental plants, and as a pest-management spray. Their use has been linked to declines in bumblebee and honeybee populations, and studies have suggested that they may be harmful to mammals as well. Following a 2012 study by the European Food Safety Association sponsored by the European Commission, 8 nations of the European Union issued a ban on the insecticide, and in 2018 a total ban was issued, except within closed greenhouses. In 2014, under the Obama administration,
the United States EPA took action to regulate the insecticide based on concerns about pollinators, which has been reversed under the current administration. 

A warming climate, habitat fragmentation, spreading fungal and bacterial diseases are also all contributing to increasingly vulnerable bee populations. 

There are actions even individual gardens and farms can make a difference by becoming more bee-friendly. If you have a small garden, you can grow plants that flower at different times throughout the year; this supports a more diverse population of bees, since different bees are active at different times in the season. If you’re a farmer, you can let cover crops go to seed–this supports bee populations by providing flowers for them to collect pollen from. You can also use caution in choosing where you plant – many bees make nests in the ground, so planting in sunny, south-facing sloped ground could damage these nests. Minimizing the mowing of long grasses in meadows is helpful, as well as not removing excessive amounts of weeds. And whether you’re a home gardener or a farmer, you can probably afford to reduce your pesticide use by turning to integrated pest management instead.

Finally, everyone can plant more natives. Since native plants have co-evolved with native bees, it’s an ideal pairing. Introducing more of these plants for wild bees to pollinate will also increase the support of the bee population. Many beautiful varieties are available for any Pennsylvania garden, from red columbines to Virginia bluebells to showy goldenrod.

From top to bottom: a bumblebee on Culver’s root,
a European honeybee on Ohio spiderwort; and a bumblebee on wild bergamot. Photos from
PSU Extension.

If you’re not sure where to start, a lot of resources are available. Pennsylvania recently published the Pennsylvania Pollinator Protection Plan, which lays out ways to protect native bee populations, among other native pollinators. It contains detailed information and resources for suburban homeowners, farmers, and municipal planners. Penn State has also started a Pollinator Garden Certification program. By following the steps outlined on their website, you can transform your garden into a haven for bumblebees. The Pennsylvania Native Plant Society is another great resource on local efforts to expand and support native plantings. For additional advice on region-specific issues, the Xerces Society’s list of resources offers many options.

You could also consider getting involved on a national scale. The Xerces Society has started a campaign called Bring Back the Pollinators, in which participants pledge to make their gardens more pollinator-friendly; they also run Bumblebee Watch, a citizen science group to track North American bee populations and collect data for conservation purposes. The Pollinator Partnership is a nonprofit running many different programs across North America, all with the goal of protecting pollinator populations. 

So next time you’re taking a walk outside, stop and smell the roses… and take a minute to be grateful for the many species bees our lives rely upon!


This POP Blog Post was written by 2019 Swarthmore student researchers Daria Syskine and Bethany Bronkema.  

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