As soon as the blue calamintha bee arrived on the scene, scientists worried it might be gone for good.
The indigo insect was last spotted in central Florida in 2016, five years after it was first identified. But this spring, just as Americans began to hunker down because of the COVID-19 pandemic, the rare blue bees, known scientifically as Osmia calaminthae, were rediscovered in the same region foraging on Ashe's calamint, a dainty violet flower that blooms in certain scrub habitats.
Chase Kimmel of the Florida Museum of Natural History confirmed the bees’ survival in March. At first, he couldn’t believe his own eyes. “It was a great feeling; those first few nights were hard to sleep due to the anxiousness and excitement,” he says. “The first few times I found the bee I couldn’t help [but] constantly question my own eyes and judgment on the diagnostic characteristics of the bee. I needed to look multiple times at the photos to confirm their identity.”
In all, Kimmel and colleagues documented just 17 rare bees and never more than three at any one time. To find these few, and record them for potential legal protections, Kimmel ventured to different sites across the Lake Wales Sand Ridge, a 150-mile long region along the dirt roads of central Florida marked by sprawling citrus groves and Bok’s Singing Tower, a 205-foot iridescent neo-Gothic structure. It’s a place where the jasmine-like scent of orange blossoms hangs thick in the air.
“The Lake Wales Ridge is a pretty specialized environment composed of unique scrub habitat that is limited in geographic extent,” Kimmel says. The flower that hosts the bee is restricted to a few of these isolated scrub pockets, predominantly along the ridge, Kimmel says, meaning the bee has probably always been restricted to a small area.
In addition to this geographic limitation, experts believe habitat loss and fragmentation have hurt the blue bee’s numbers in recent decades. “This ancient island ridge is now primarily composed of agriculture, typically citrus, and urban development,” Kimmel says. “While we have no evidence of pesticide exposure, it is highly likely that the bees could be impacted by this adjacent agriculture given that they have been found only meters away.”
Because blue calamintha bees have been known for only a decade, scientists are still getting to know more about their vulnerabilities and idiosyncrasies. For example, the bees appear to have an unusual way of foraging. They tend to rapidly bob their heads two to four times when visiting flowers. Kimmel and other experts believe they do this to dislodge pollen from the plant, but none of the other 23 bee species known to visit Ashe’s calamint do this, Kimmel says.
“This behavior also results in some of the bees carrying pollen on their face for extended periods of time, which is also rare,” he says. “It’s quite strange that it doesn’t groom itself more often and transfer the pollen to its abdomen sooner. The hairs on its face to appear modified for collecting pollen but this would need additional studies to see if that is the case."
Furthermore, Kimmel and colleagues don’t know exactly why the bee got its indigo coloring. It is among at least nine species of bees in Florida that have blueberry-like exoskeletons. The indigo league is made up entirely of “spring-flying” bees, which is why studying the blue calamintha bees in March was so important. The solitary bees (a hive has never been found for them) have only ever been documented in the wild from March 9 to April 30.
Insects, especially rare ones, are difficult to study over time to build population estimates because of their small size—this is exacerbated when a particular species is active only for a small window of time each year. Nevertheless, Kimmel and his team are collecting as much data as possible about the 11-millimeter blue bee so the United States Fish & Wildlife Service can determine whether this rediscovered species qualifies to be listed under the Endangered Species Act. The non-profit NatureServe already designates the bee as “critically imperiled,” but it needs official federal status to gain legal protections.
“I feel very happy to hear that the bee was rediscovered,” says Molly G. Rightmyer, whose team first identified Osmia calaminthae nearly a decade ago. “Doing systematics work [describing species and determining evolutionary history] sometimes feels a bit isolated and esoteric, so to know that people were spurred to action—that people actually cared enough to go looking for this bee—is very heartening.”
Although Kimmel currently doesn’t have a good estimate of how many blue calaminthas remain in the wild, he remains hopeful that the brightly colored bee will make a comeback in the coming years. Back in 2011, when the bees were described by Rightmyer, they were found only in four locations in Highlands County, a range that totaled a paltry 16 square miles. Today, Kimmel says, he found the blue bees, without the aid of volunteers (coronavirus impeded them from joining), in three of the original sites plus an additional seven properties that are protected for wildlife. The bee was also been observed in neighboring Polk County, which extends its known territory.
These sightings expand the bees’ range “much farther north” than their previous known territory, which could indicate they are hanging on in the face of multiple threats—perhaps just in time to be researched and protected.
“It can get very hot, and one can feel pretty exhausted being out in the scrub habitat for extended periods. But it’s worth it,” says Kimmel about his ongoing research. “Because every time I find the bee it’s exciting to know that we are getting a better understanding of it and helping it.”