The beautiful, intricate relationships between native bees and native food crops

This week on the Local Food Report . . . LISTEN TO THE FULL REPORT

For most of her career, biologist Jennifer Forman-Orth at the Massachusetts Department of Agricultural Resources has been focused on invasive species. But in 2015, a colleague asked her to help make a poster of all the native pollinators in our state and the plants they like to visit, and suddenly, her focus shifted.

"And I was helping him work on that. And that kind of turned into a realization that there was this desire by the public to have more resources that they could access for native pollinators, and the best resources for native pollinators are native plants."

Often when we talk about these plants, we talk about non-edible species. And these are important for reasons we’ll get to in a few minutes. But Jennifer says that many of our native bees — and a few other surprising insects — actually evolved with and rely on many native edible species.

"There's mining bees. Mining bees are actually active right now," she explained.

"They come out first thing in the spring and they pollinate plants like blueberries and there are squash bees, which are actually my favorite kind of bee. They're a type of long-horned bee. They have really long antennae and they primarily pollinate cucurbits. So plants in the squash family, like zucchini and cucumber and pumpkin and things like that."

Mining bees and squash bees have co-evolved with their host plants in ways that make pollination more effective and efficient. Mining bees for instance perform something called buzz pollination — a particularly effective way of shaking blueberry flowers — and a movement that honey bees just can’t do. Squash bees feed their young exclusively with squash pollen, which has chemicals that make it distasteful to many other bee species. And then there are native bumble bees — the Bombus genus.

"And bumblebees are actually the chief pollinators of tomato plants and other related plants in the same family, so. Eggplant and pepper. And a lot of people don't realize that in places where there are no bumblebees, but they're trying to grow tomatoes, they often have a mechanical device that they use to vibrate the tomato flowers at the right frequency, the same frequency that matches what bumblebees do when they're pollinating them. Otherwise they don't produce fruit."

The list of connections goes on. Black flies, it turns out, also pollinate blueberries. Beetles pollinate paw-paw trees. Sweat bees pollinate stone fruits and sunflowers. And in order to do all this crop pollination, these bees and other insects need a wide variety of native plants — not just edible species — to keep their populations large and healthy.

"So you want to make sure there are pollen and nectar resources available not just when the tomatoes are in flower but all season, the whole time that the bees and other pollinators are active. And that means looking at things like willows, so that’s a tree or sometimes a large shrub that provides both pollen and nectar for bees and other insects in early spring at a time of year where there’s not a lot of other resources available."

It's also important for gardeners to provide nesting habitat — we can do this by planting native clumping grasses, leaving open small areas of dirt or sand for ground nesters, and keeping dead flower stalks and stems standing until early summer. And last but not least, Jennifer told me, we can think about something I’ve definitely never thought about before which is the fact that bees have tongues!

"They exist and some of them are long and some are short and some medium. And they've evolved to go after the nectar and flowers based on the length of their tongue. So the longer the tongue, the longer of the flower they want to go for."

Because of this, Jennifer told me, in order to support the widest diversity of native pollinators — which remember, are critical for so many of our beloved native food crops — we want to not only provide nectar and pollen in the form of flowers all season long, but we also want to plant a wide variety of flower shapes, sizes, and colors — picture not just a few violins but a whole orchestra.

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Here's a link to a list of plants that help support endangered bumblebees.