The last Franklin's bumblebee was found by Robbin Thorp in 2006.

The last Franklin’s bumblebee was found by Robbin Thorp in 2006.

Jes Burns, OPB/EarthFix

If an octogenarian entomologist could be a superhero, Robbin Thorp might be a good candidate.     

He moves slowly along the Pacific Crest Trail, eyes scanning below a floppy field hat. In his hand, a hero’s gadget – what appears to be a ray gun, straight out of the comics.   

But this gun sucks instead of shoots.  

Thorp spots a female worker bee with big pollen loads on her back legs, aims the gun and pulls the trigger. In a whir, the bee is sucked up into the gun’s clear plastic barrel.   

“They don’t like to be imprisoned for a while, but other than that it doesn’t hurt them,” he says. 

Then Thorp uses the gun’s other feature, a magnifying lens, to identify the bumblebee trapped inside the chamber. It’s not Bombus franklini, the bumblebee Thorp has traveled to Mount Ashland to look for; the bumblebee he was the last person on the planet to see alive.   

So he lets her go.

Bee-dle In A Haystack  

Some creatures are so small and difficult to track that it’s hard to tell if they’ve gone extinct. That’s the case for Bombus franklini, or Franklin’s bumblebee. It once ranged from Roseburg, Oregon, south to Mount Shasta in California. But no one has seen it since Thorp caught one in this Mount Ashland meadow in 2006.   

“Aug. 9, just down the [Pacific Crest’ Trail. On the other side of the seep down there,” Thorp recalls. “That got my heart rate going.”  

The retired University of California, Davis entomologist isn’t giving up on the bee. He still makes an annual pilgrimage to Mount Ashland in hopes the Franklin’s will make an appearance once again.  

For this mission though, even a superhero like Robbin Thorp needs sidekicks. He has about 30 from different federal agencies and nonprofits.  They’re waiting for their marching orders, butterfly nets in hand, on national forest land near the Oregon-California border.  The wildflowers that surround them are putting on a show.

Jeff Dillon with the U.S. Fish and Wildlife Service organized the congregation — or “cape” if you will —  of sidekicks.

“Hopefully this will be the year we find the Franklin’s,” Dillon says. “If you think you have captured one of those, please get it back to Dr. Thorp right here. He’s our authority on the species.”

Thorp has been surveying for the bee for two decades. He saw the population of Franklin’s and another related bee, the western bumblebee, dropping in the early 2000s.

“I already knew (the Franklin’s) had declined by the time I saw that (last) one. It had gone missing for several years before then,” Thorp says. 

It’s not just the Franklin’s bumblebee population that’s crashed. Worldwide, bees are facing significant challenges due to habitat loss, pesticide use and climate change.

This is the height of wildflower and bumblebee season on the meadows of Mount Ashland. 

This is the height of wildflower and bumblebee season on the meadows of Mount Ashland. 

Jes Burns, OPB/EarthFix

This year, for the first time, a bumblebee was listed under the U.S. Endangered Species Act. The rusty patched bumblebee was once found across the eastern United States and upper Midwest, but the population has dropped 87 percent in the last 20 years. 

The Franklin’s bumblebee is currently “under review” to determine whether an ESA listing is warranted.

Thorp hypothesizes that disease caused the disappearance of the Franklin’s and western bumblebees in this region.

“Any species that disappears is always a big deal, to me anyway. And it’s of concern when one or more start declining. And in this case, there’s a couple of very closely related bumblebees that have declined in the West,” he says.

This is also of concern because bumblebees are important pollinators. They work flowers differently than honeybees. It’s a specialized way that’s called buzz pollination.

“They go up to the flower. They grasp it. And then they buzz. And the certain frequency, usually the note of C, and the pollen comes out like a salt shaker. And then the bee is coated in the pollen and it pollinates that flower,” says Kristi Mergenthaler with the Siskiyou chapter of the Native Plant Society.  

About 8 percent of the world’s flowers are buzz pollinated, including Northwest agricultural mainstays like blueberries, cranberries and potatoes.

Robbin Thorp explains why he believes the Franklin's bumblebee has disappeared for so long.

Robbin Thorp explains why he believes the Franklin’s bumblebee has disappeared for so long.

Jes Burns, OPB/EarthFix

On A Mission

The hopeful bumblebee hunters disperse into the meadows, swiping at purple mint flowers with nets.

“You can actually sit and watch and have [the bumblebees] come to you, but I usually go to them,” says Brendan White with the U.S. Fish and Wildlife Service.

White has been helping with these surveys for a while. He demonstrates to a few new sidekicks a sting-avoiding technique for transferring bumblebees from net to vial for identification.

“Surveying for rare bumblebees [is] a little bit difficult because they’re spread out over a large area. You can miss it by 10 feet. You could miss it by 10 days,” he says.

To make it even more difficult, differences between species are often subtle.

“With these bees, it can be where a stripe is, or is there an extra little divot somewhere,” says volunteer Alison Center, president of the Oregon chapter of the North American Butterfly Association.

This is the peak of bumblebee season in these meadows and bees are everywhere. Every close examination brings hope the lost bee is back.  

Last year, the bumblebee hunters saw two western bumblebees – an exciting find. The bee is considered “critically imperiled” in the Pacific Northwest and its population is estimated to have declined more than 70 percent in the past two decades. It started to decline on Mount Ashland around the same time as the Franklin’s.

“Looks like the western is perhaps in recovery, and it gives me some hope that maybe Franklin’s is also. And it’s just out there under the radar,” Thorp says.

And that’s the way the quest of this superhero goes: One day you find a Franklin’s bumblebee, but most days, this one included, you don’t.

The last Franklin's bumblebee ever seen was just south of this spot near the Pacific Crest Trail on Mount Ashland.

The last Franklin’s bumblebee ever seen was just south of this spot near the Pacific Crest Trail on Mount Ashland.

Jes Burns, OPB/EarthFix