Parasite zombie flies and a honeybee; courtesy of John Hafernik/SF State University

Zombie bees are not science fiction. They are real—and real threat to already-threatened U.S. honeybee populations.

Honeybees (Apis mellifera) in California and South Dakota have been observed acting zombielike, wandering away from their hives at night and crawling around blindly in circles.

These insects have been rendered insensate by a parasitizing fly that lays eggs in the bees’ bodies. After the bee dies a lonesome death, pupae crawl out and grow to adult flies that seek new bodies to infect.

Such a sight startled John Hafernik, a professor of biology at San Francisco State University, when he looked at dead honey bees he had collected on campus. He soon started noticing clumps of dead bees under light fixtures in the area. He and his colleagues found that this bizarre bee behavior was the result of the fly Apocephalus borealis (they described their findings in January in the journal PLoS ONE). After sampling hives around the Bay Area, they found that, disturbingly, more than three quarters were infected with this parasite.

Honeybee colonies have been collapsing at an alarming rate in the U.S. for the past several years. And without these important pollinators, many of our favorite foods, from almonds to zucchini would be difficult to produce. Scientists have implicated viruses, fungi, mites and other invaders in colony collapse disorder, but Hafernik suspects this parasite is a new villain on the scene. “Honeybees are among the best-studied insects,” he said in a prepared statement in January. “We would expect that if this has been a long-term parasite of honeybees, we would have noticed.”

How do you catch a zombie bee? A "ZomBee" trap; courtesy of John Hafernik/SF State University

Now, to see how far the zombified bee problem has spread, he and his colleagues are enlisting the help of the whole continent. They have launched ZomBeeWatch.org, a citizen science project that allows people to help them track suspicious bee behavior and collect specimens. Through the project, which launches in full today, they are hoping to find “if this parasitism is distributed widely across North America,” Hafernik said in a new statement.

To help out, you can sign up to collect sick-looking or dead bee specimens and observe them to see if parasite fly pupae emerge. Industrious citizen scientists can build light traps to attract any parasitized bees in their area (full instructions are on their site). And the researchers promise that even bees that do not turn out to be true “ZomBees” are important to report in an effort to better understand contributors to colony collapse.

“If we can enlist a dedicated group of citizen scientists to help us, together we can answer important questions and help honeybees at the same time,” Hafernik said.

Not sure what a zombie bee looks like? Here’s a video clip of a sick bee: http://www.youtube.com/watch?v=xs32DCaxU1U&feature=youtu.be (Read more about parasites that make their hosts act like zombies in the article “Zombie Creatures.”)

In case you’re wondering what we’ve been wondering—ahem, what else can these zombie flies infect?—ZomBee Watch has an answer: “The zombie fly only parasitizes insects and does not lay eggs on or in humans,” according to its website. “As far as we know, it does not transmit any diseases that are contractible by humans.” As far as we know…

Read more about how to join ZomBeeWatch.org on our Citizen Science page.