The Hidden Lives of Solitary Bees: Uncovering Nature's Lesser-Known Pollinators

Student Spotlight: Orion Pizzini

By Grace Tiwari

In a world where honey bees and bumble bees steal the spotlight, Orion Pizzini, a master's student in the Grozinger lab, is turning attention to their lesser-known cousins – solitary bees. These remarkable insects, which make up 90% of the world's 20,000+ bee species, live and work alone with no queen or sisters, yet play a crucial role in maintaining natural ecosystems. 

"Whenever I get to share my research, people are taken aback by the idea that there is such a thing as solitary bees. Most people assume all bees are social like honey bees and bumble bees. My goal is to learn more about solitary bees so we can show the world just how cool and important they are" says Orion. 

Unlike their social cousins who live in bustling hives, solitary bees are independent operators. While 70% of the solitary bee species nest in the ground, Orion's research focuses on the solitary bees that nest in the above-ground cavities. Each female serves as her own queen, nurse, and forager. The female emerges in the spring to find a mate and establish a nest in whatever suitable cavity she can find – be it a hollow plant stem, abandoned beetle burrow, or hole in a tree. There, she carefully provisions each "brood cell" with pollen and nectar, lays an egg, and seals it off with materials ranging from mud to carefully cut leaves, depending on her species. 

To study these elusive insects, Orion has established a network of "bee hotels" – artificial nesting structures – across different environments. His fieldwork involves meticulous daily monitoring of these hotels to observe which species nest there, their preferred nesting locations, and their nesting behaviors. In the lab, Orion collects pollen samples for analyzing the nutritional content and performs meta-DNA barcoding to identify the plant sources of the pollen. This dual approach reveals not just where the bees forage, but also what nutrients they're seeking for their offspring. The nesting materials also tell an important story - for species that use leaf cuttings or plant resins, DNA analysis can trace these materials back to their source plants, offering a complete picture of the bees' foraging behavior.

"Understanding and protecting solitary bees is crucial for maintaining global biodiversity," Orion emphasizes. "While managed pollinators like honey bees get most of the attention, these independent bees are the quiet champions keeping our wild ecosystems alive."

Through this research, Orion hopes to develop better conservation strategies that support these essential yet overlooked pollinators, ensuring their continued role in maintaining the delicate balance of our natural world.

"Every bee has her own personality and preferences; some are incredibly particular about their nest sites, while others are more adaptable. Understanding this individual variation is crucial for conservation efforts." 

Orion Pizzini is a Master's student in the Entomology Department at Penn State, advised by Dr. Christina Grozinger and Harland Patch. His research is funded by support from the Wyman's of Maine, as well as the Penn State College of Agricultural Sciences and Huck Institutes of the Life Sciences.