The Secrets of Bee Foraging: How Flower Choices Affect Bee Behavior and Biodiversity (Ep. 53)

One of the simplest and most effective ways to support native bees is to plant a diverse array of native flowering plants. These plants provide vital food, shelter, and nesting resources for bees throughout the changing seasons. As key pollinators, bees form mutually beneficial relationships with flowering plants, ensuring biodiversity and food security in ecosystems. However, the alarming decline of flowering plants is putting these essential interactions—and pollinators themselves—at risk.

In this episode, Dr. Jaya Mokkapati joins us to share her research into the foraging behaviors of solitary bee species. Her work offers new insights into how different bees prioritize their choices, whether focusing on the quantity of flowers or the nutritional quality of pollen. Understanding these behaviors can inform conservation strategies, such as planting flowers tailored to meet the needs of various pollinator species.

Dr. Jaya Mokkapati is a postdoctoral researcher at Pennsylvania State University in the US. Learn more about the work she does and follow her on X (formerly known as Twitter.)  You can read more about Jaya’s study on foraging bees here.

For more insight into plant-pollinator relationships, check out our previous episodes including discussions on native vs. non-native plants and the effects of plant pollinator mismatch. 

Good to know

Jaya’s study involved two types of solitary bee species, studied in the lab. Osmia cornifrons, or the horned-faced mason bee, helps pollinate crops like apples and blueberries. Despite their threatening sounding name (they actually do have horn-like extensions protruding from their lower face) they are a fairly docile species of solitary bee. 

Megachile rotundata, known as the alfalfa leafcutting bee, doesn’t only pollinate alfalfa, but also carrots and other vegetables. It’s known for being a very efficient pollinator.

Transcript

[00:00:00] Welcome to the Bees Knees. A podcast wild about native bees. Wild and native bees are under threat worldwide. In each episode, we look at actionable things we can do to support these adorable little guys whose pollination work is crucial for maintaining biodiversity. I’m Jacy Meyer, and I thank you for being here.

Pollinator plant interactions are the cornerstone of biodiversity in ecosystems. Pollinators play a vital role in sustaining life as we know it, but the decline of flowering plants is pushing these relationships to the brink. How do bees choose the flower they visit? Is it about quantity, the number of blossoms or quality, the nutritional value of pollen?

Today I’m talking with Dr. Jaya Mokkapati , who studied this intricate dance between plants and pollinators. I started our conversation by asking Jaya about the different factors that influence bee foraging decisions. [00:01:00]

Well over millennia, bees and plant flowering plants have developed a crucial, mutually beneficial relationship.

Essential for biodiversity and food security. Bees collect nectar and pollen, uh, for their food while helping plants reproduce by spreading pollen. But over the last few decades, pollinator populations are declining, partly due to the loss of flowering plants and previous studies from our lab showed that certain bumblebee species forage across differing flowering plants to obtain pollen.

However, these studies, uh, primarily examined how bees collected pollen while controlling for flower size or quantity. So it’s still unclear whether these bees prioritize the number of flowers or the nutritional quality of the pollen when foraging. So this uncertainty inspired us to [00:02:00] explore how bees prioritize their choices and whether these preferences can vary between species.

As different solitary bees. may focus on nutrition in different ways depending on their individual needs and environments. Ultimately, understanding these preferences help us restore pollinator habitats and support the populations.

Can you explain how you use different types of plants in your study To discover what attracts bees the most?

Fortunately for our study, we were able to collaborate with the Dr.Adrien Sicard,. A from the Swedish University of Agricultural Sciences. The Sicard Lab have created a special group of plants, recombinant plants, uh, generated by like from capsular, two capsular species. So they crossed these two species, one that can self-fertilize, and the other that relies on pollinators to reproduce.

So. This, the breeding scheme that generated these recombinant inbred lines resulted in [00:03:00] different floral traits being uncoupled from each other in the lines, which allowed the study to how, like how changes in flower characteristics precisely like quantity versus quality influence. The bee visits in our study.

So your research found that different bee species do have different flower preferences, but could you tell us about what each species you studied preferred and why you think they make the choices They do.

Basically we found that uh, one species, Osmia cornifrons , a mason bee species that preferred plants with more flowers while Megachile rotundata, which is a leaf cutting bee species, focused on the nutritional quality of the pollen.

Favoring flowers with higher ratios of protein, to lipid and additional studies, uh, with artificial flowers confirm that Megachile indeed consistently choose high protein to lipid ratio diets while Osmia did not, which is very [00:04:00] surprising. The difference in these foraging behavior between like these two species emphasize how the timing of the resource availability shapes bee preferences.

Instance, like Osmia cornifrons spring bee, so it faces limited food resources and is likely to prioritize the quantity of flowers to meet their nutritional needs in short window of time during their foraging. On the other hand, Megachile rotundata , which is a summer bee species with access to more abundant resources, so it can afford to actually be more selective and focus on the nutritional quality of the pollen.

This suggests that the ascend like seasonal foraging habits could have played a crucial role in shaping bee behavior and potentially influencing how different bee species interact with plants based on their resource availability. So we are now developing hypotheses for why these species prefer in their foraging [00:05:00] strategies in terms of their sensory and cognitive recognition processes.

And how these different strategies evolved in our next studies.

Based on your findings, what practical steps can gardeners or policymakers take to create environments that support both bee species and plant biodiversity?

Um, by understanding these how different bee species forage, we can guide conservation efforts by planting a variety of flowers that cater to the.

They like specific needs, which is essential for supporting their pollination. For instance, like land managers, they can create habitats that ensure food resource, food sources for all available throughout the seasons and promoting healthy ecosystems. Educating public and stakeholders about the specific needs of these.

bee species can encourage support for initiatives like native plant gardens and other efforts that create pollinator friendly environments. [00:06:00] So by raising awareness of these, how these gardens can provide essential resources for bees, we can inspire the community involvement and commitment to. Like preserving local biodiversity in their like local habitats.

So this collective effort, not only benefits the bees, but also enhances the beauty and ecological health of our surroundings ..

So one thing, like our study also highlights the need for like, more research on seasonal foraging, as I said before, like, yes. So how these like with, uh, the, these seasonal foraging habits among various bee species change and like, which can deepen our understanding of the vital role in pollination and plant reproduction.

And finally, if you could encourage people to do just one thing to support native bees, what would it be?

To support native bees? Yeah, I would encourage planting a diverse range of native flowering plants in their gardens, yards and public spaces. [00:07:00] So native bees on, rely on only native plants for food, shelter, and nesting sites by choosing local pollinator friendly flowers, shrubs, and trees, for example, like cornflower bee balm, eastern redbirds or goldenrod or milkweed.

So we can create a thriving habitat that supports important pollinator survival. So these plants provide essential nectar and pollen through different seasons. So ensuring that bees have the steady food source for them to actually explore in their habitats. And small efforts like these actually, uh, in both urban and rural areas can make big differences in protecting and preserving these crucial pollinators for future generations.

The strategies that the two solitary bee species Jaya studied, and the reasons they choose the flowers they do, isn’t just about understanding bees and flowers. It’s about biodiversity and ensuring a healthy, [00:08:00] balanced ecosystem. As Jaya mentioned, there’s still a lot more to investigate if we truly want to support native bees and native plants.

My thanks to Jaya for sharing her insights and to you for tuning in. Be sure to visit the website, the Bees Knees website to learn more about the two bee species Jaya mentioned. And there are also recommended past episodes about plant pollinator interactions for you to check out. Jaya’s actionable advice is to choose your native plants to support your native bees.

Until next time, choose wisely.