[Bonus] Short - Dr. Dewey Caron, "Honey Bee Communication Dynamics"

[Bonus] Short - Dr. Dewey Caron, "Honey Bee Communication Dynamics"

Dr. Dewey Caron: Hi. I am Dr. Dewey Caron. I come to you from Portland, Oregon. I present another audio podcast on communication in my continuing series to monthly of the Beekeeping Today Podcast. Topic this month, which I'm recording as Spring's fourth, centers around foraging. For these audio postcards, I've been discussing communication on three levels, bee scientist to beekeeper, beekeeper to bee , and bee to bee.

Let's start with bee scientist to beekeeper. The scientist is Dr. Priyadarshini Chakrabarti Basu, or, as we know her, simply as Priya. She was a postdoctoral student at Oregon State University after finishing her PhD in India and, just at the beginning of this year of 2025, moved from Mississippi State University to Washington State University in Pullman. She studies multiple stressors that affect honeybee health, including her unique exploration of honeybee nutrition. She was at the Beekeeping Today Podcast on number 309, which was recorded and presented in mid-December last year, 2024.

In our podcast with Jeff and Becky, she discussed the collaborative effort of various research collaborators, partners, and citizen scientists for creating the first bee nutrition database for North America. How does this relate to bee foraging? While Priya was at Oregon State, she and Dr. Ramesh Sagili had USDA grant funding to determine the nutritional adequacy of over 100 pollen sources. These were collected actually from the legs of foraging worker honey bees. Both macro and micronutrients of pollen was determined from the pollen pellets via the sophisticated laboratory analysis that she's capable of doing.

In essence, developing something like you might see on a nutrition label of your favorite foods, but for bee-collected pollen. The analysis of amino acids, the minerals, the steroids, et cetera, a pollen is then used to build a database on what bee-collected pollen from specific identified plants might contribute to the bee diet. Although we might see bees collecting pollen from a specific plant, it doesn't necessarily mean it might be capable of furnishing the complete diet that the bee might need. It might be the closest plant to the bee hive, or it might be a flower that a foraging bee can more easily access to collect pollen, for example.

Other factors might influence what we can see and we can measure as influencing incoming pollen. Nectar foraging is the default behavior of foragers. Pollen collection, however, is a response to two major colony stimuli. One, the presence of brood pheromone in the colony, and two, the existing amount of pollen that is after it's been converted to bee bread currently stored in the beeswax cone. There's a strong component of colony genetic makeup that influences pollen foraging. For example, number of people have shown it's easy to demonstrate that pollen foraging can be selected.

You start with a high collecting and a low collecting, and then only three or four generations of selective pressure can show differences among those two. Those with the high will be collecting more pollen of all sorts of pollens and the other less. During food scarcity dance language, the method foragers use to recruit more foragers to a flowering species has a lower response threshold. They're able to recruit foragers to less desirable sources, for example. Several researchers have shown foragers from stronger colonies, that is, a population of more bees, fly further distances seeking pollen compared to weaker colonies.

The dance floor, which is usually the lower beeswax home surfaces of a hive, becomes larger in stronger colonies and when food is in short supply. All of this means what we might measure for incoming pollen is strongly influenced by conditions in that highly social bee colony. I recommend that you check out the way that she is building this database. That was in Beekeeping Today Podcast, number 309.

Study of foraging by honeybees and development of nutritional databases and seasonal phenology of what pollen sources are available to bees, particularly that are nutritionally valuable, can help us as beekeepers and others, such as conservationists, determine what might be more appropriate type of flowers to plant for bee forage. A more comprehensive knowledge of the nutritional status of the plants bees frequent will help bee conservation groups, land managers, beekeepers, crop producers, and the general public better manage these critical pollinators and lead perhaps also to much more efficient pollination services for those numerous plants that we grow that need pollination service as the courtesy of honeybees.

Let's move to beekeeper to bee communication. Honeybees use nectar to drive their muscles, that's their energy source, permitting them to accomplish their hive activities initially in their adult lives and then to forage for flowers that help meet their nutritional needs. Although we can supplement a colony's diet, it is the foragers of a colony that the entire bee family of the colony is dependent upon to obtain a nectar and pollen needed in their diet. Nectar and pollen, along with foraging for propolis and water, is the work of the older age foragers of the colony.

Foraging behavior is as age-dependent, we know for the older bees, and is modulated by chemicals such as the hormones, particularly juvenile hormone within the bee system and vitellogenic. Foragers collect nectar continuously to build large honey stores for overwintering. On the other hand, pollen foraging builds more modest stores of bee bread for brood production for those next generations. Nectar foraging can be considered a supply-driven process, whereas pollen foraging is demand-driven.

Study of foraging by honeybees in development of nutritional databases and seasonal phenology of what pollen sources are available to bees that are nutritionally valuable can help beekeepers and conservationists determine what might be more appropriate types of flowers to plant for bee forage. A more comprehensive knowledge of the nutritional status of the plants bees frequent and forage may help bee conservation groups, land managers, et cetera, including us as beekeepers, to help manage and supply food for the critical pollinators. Lack of forage opportunities is considered one of the major factors contributing to bee decline, something we have unfortunately witnessed these past two seasons.

We've been having information on the very heavy losses, particularly these last two years. The stress of inadequate nutrition can act directly where hungry bees are unable to meet their nutritional needs or indirectly where the resulting nutritional stress reduces the bees' ability to cope with other stressors such as the Varroa mites, diseases, and pesticides. By observing bees examining their pollen collecting, we can be asking our bees what are the more valuable plants in their diet. There exist several published lists of plants that are supposedly good for pollinators, but these lists often are not referenced by peer-reviewed research. It is impossible to evaluate the data to make more informed decisions.

Recommendations usually contain a mixture of commercially available ornamentals and more wild-type mixes raised from seed, the establishing maintenance of which is labor and scale-intensive rendering that mass and less useful to the citizen user. From experience, we know that several plants that are frequently found on such lists are not actually good for pollinators.

Thus, there's a critical need to run a choice experiment to determine which garden plants are most effective at attracting the most number of individual visitors, whether it's pollen or nectar, and the most diverse group of different species, not only bees but also other pollinators and the effect of native versus non-native status of plants on a type of pollinator visitor. Then, we need to continue to develop this nutritional value database. We need to ask our bees and then do the analysis.

Finally, bee-to-bee communication. I've been talking about studies here on the West Coast, with Priya now at Washington State, continuing those studies. On the upstate coast, Virginia Tech University Associate Professor Margaret Couvillon maintains that just planting more flowers might not improve bee health because we do not fully understand how bees are foraging in their existing landscape. Dr. Couvillon and her students investigate the dynamics of how pollinators collect their food, with a specific focus on honeybee foraging recruitment and health.

She deciphers how bees talk to one another. Their methodology uses honeybee waggle dances, which are the means of successfully recruiting naive bees, new foragers. Then they communicate to their nest mates. They have very specific information of distance and direction from their hive to the discovered flowering resource. These dances are visible to the eye and can be decoded, analyzed, and mapped. Then this enables the researcher to determine where bees are and are not foraging. With such precise data, it's possible to implement a best management strategy for improving food availability to benefit overall pollinator health in a meaningful, targeted way.

Compared to other pollinators, honeybee foragers are capable of leaving their hive and foraging over long distances. A honeybee forager may collect from a resource 2 or more miles away from the hive on an extended trip of few to many minutes in time. The waggle dance, that very simple but very elegant behavior of one bee talking to another bee, permits the bees to take such foraging excursions and permit eavesdropping by researchers such as Dr. Couvillon and her students to know where the bee has gone to collect food. I think it is just totally cool how honeybees, unlike other animals, can actually tell you where it has been.

Foraging, the bee postcard for the month. I hope you will be well. Trust your bees will find nutritionally adequate flowering sources and this spring grow into healthy honey-storing colonies early this season. Thank you.

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