The Cockerell's bumblebee is finally generating some buzz again this week, more than half a century after the species supposedly vanished. Scientists from the University of California-Riverside have rediscovered the bee living in the White Mountains of New Mexico, ending a five-decade fugue for America's rarest bumblebee.
The species was first identified in 1913, based on six specimens collected around south-central New Mexico. Another 16 were later discovered nearby, most recently in 1956, but then no more were seen for the next 55 years. This led many scientists to assume the species had died off, which wasn't far-fetched — the Cockerell's 300-square-mile habitat is the smallest range of any bumblebee species in the world.
On Aug. 31 of this year, however, researchers from UC-Riverside found three Cockerell's bumblebees on some weeds along a highway north of Cloudcroft, N.M. DNA sequencing now confirms they're from the same "extinct" species first discovered 98 years ago.
So how did this bumblebee fly under the radar for so long? As UC-Riverside scientist Douglas Yanega explains, the small number of specimens discovered before its disappearance had led to confusion about whether it was a distinct species.
"Most bumblebees in the U.S. are known from dozens to thousands of specimens, but not this species," Yanega says in a press release . "The area it occurs in is infrequently visited by entomologists, and the species has long been ignored because it was thought that it was not actually a genuine species." But thanks to modern technology for analyzing DNA, he adds, "these new specimens give fairly conclusive evidence that Cockerell's bumblebee is a genuine species."
The U.S. is home to nearly 50 native bumblebee species, some of which really are at risk of extinction. The Franklin's bumblebee, for example, hasn't been seen since 2003, and it's one of four U.S. species that have suffered "catastrophic declines" in the past decade, according to the Xerces Society for Invertebrate Conservation .
Several other U.S. bumblebees are also in decline, a mysterious trend that's often overshadowed by the similar loss of U.S. honeybees . Although the reasons for both problems remain unclear, studies have pointed to pesticides, habitat loss, climate change and competition from non-native bees. Like honeybees, bumblebees are also a key pollinator for many flowering plants — including food crops — meaning a prolonged die-off could be an economic disaster as well as an ecological one.
But while U.S. bumblebees are at risk overall, Yanega thinks Cockerell's bumblebee is stable for now. "Given that this bee occurs in an area that's largely composed of National Forest and Apache tribal land," he says, "it's unlikely to be under serious threat of habitat loss at the moment." And it's not unusual for a species to disappear and reappear like this, he adds, especially if it's an obscure bug. "When an insect species is very rare, or highly localized, it can fairly easily escape detection for very long periods of time. ... It is much harder to give conclusive evidence that an insect species has gone extinct than for something like a bird or mammal or plant."
Still, the Cockerell's long absence has left a void of knowledge about a bee that might not be as safe as it seems. Its biology is "completely unknown," Yanega says, and "may require some more formal assessment" down the road. "The first step is to come to a firm conclusion regarding the status of this bee as a species. The second step is spreading the word to the scientific community that this bee deserves some attention, as it has been completely overlooked."
Also on MNN: