Tracking a Parasite that Turns Bees Into Zombies

The New York Times    By Nicholas St. Fleur    February 25, 2016

A female parasitic Apocephalus borealis fly about to infect a honey bee with its eggs. Credit Christopher Quock

Call it “The Buzzing Dead.” Infestations of what scientists have dubbed “zombie bees” have spread across both the West and East coasts in recent years.

The honeybee hordes, while not actually undead, are the unwilling hosts to a parasite infection that researchers think drives the drones to act erratically, or “zombielike,” in the moments before they die.

To better understand the parasitized swarms, John Hafernik, an entomologist at San Francisco State University has recruited people countrywide to join his hunt.

“The big question for us was, ‘Is this a San Francisco thing?’ Or something that is taking place all over the country that has not been noticed by biologists before,” he said.

Since he began the project four years ago, he has concluded the answer is the latter. Volunteers have helped identify infected honeybees in California, Washington and Oregon as well as Vermont, Pennsylvania and New York. More than 800 bee observations have been uploaded to the ZomBee Watch online database.

Dr. Hafernik first discovered something eerie was happening to the bees on his campus in 2008 when he stumbled upon several of them staggering in circles along the sidewalk. For weeks he picked a few up and placed them in a glass vial with plans to feed them to his pet praying mantis.

One day he came across a vial he had forgotten on his desk for a couple of weeks. The bees inside were dead, but the vial was overwhelmed with small brown fly pupae. He came to the realization that the bees were parasitized.

 Fly maggots bursting from a parasitized honey bee. Credit John Hafernik

After further exploration across San Francisco Bay, he and his colleagues found several bees that were also behaving strangely. They would fly from their hives at night, which was something bees would normally never do, and then circle around a light fixture. After their nocturnal dance the bees would drop to the ground and start walking strangely. They were succumbing to their overlord, larvae of the fly Apocephalus borealis.

The life cycle of the parasitic fly is straight from a horror story. The female fly uses something called an ovipositor, which is like a hypodermic needle, to inject her eggs into the abdomen of the honeybee.

About a week later the larvae lurking within the abdomen wriggle into the bee’s thorax and start liquefying and devouring its wing muscles. Then, like in the movie “Alien,” they burst through the bee’s body, erupting from the soft space between its head and shoulder area.

“As far as we know this is a death sentence,” Dr. Hafernik said. “We don’t know any bees that have survived being parasitized by these maggots.”

As many as 80 percent of the hives that Dr. Hafernik examined in San Francisco Bay had been infected. Understanding more about how the infection spreads is important, he said, because although the infestations are not the main driver behind honeybee declines across the country, they could help collapse an already vulnerable colony.

Help Researchers Find Out Where Zombie Bees Are!!!

LACBA Newsie Bits  By Stacy McKenna   February 12, 2016

Help researchers find out where ZomBees are happening with the ZomBee Watch citizen science project. Brian Brown of the Natural History Museum of Los Angeles County, one of the discoverers of the ZomBee and the parasitic fly that causes them, is one of the researchers and this project was named one of Discover magazine's Top Ten citizen science projects of the year. 

(If you prefer spiders, snails, lizards, squirrels, or other forms of local wildlife, NHM has a variety of citizen science projects you can help out with!)

Parasitic Honey Bee Discovered for the First Time in Mid-Atlantic Region   By Jonathan Morales    November 3, 2014

Parasitized honey bees, or "zombees," have been found for the first time in the mid-Atlantic region, according to researchers at San Francisco State University. The discovery, made in Mountain Top, Pennsylvania, was announced this morning by ZomBee Watch (, a project based at the University.

SF State Professor of Biology John Hafernik and his colleagues first reported parasitized honey bees in 2012 in an article in the journal PLOS ONE. After being infected with a fly parasite, the bees abandon their hives to congregate at night near lights, dying after a bout of disoriented, "zombie-like" behavior. Hafernik and other researchers are tracking the phenomenon with the help of more than 2,000  who report possible parasitized bee sightings to ZomBee Watch.

Early zombee sightings were mostly limited to the U.S. West Coast and South Dakota. Last year, however, researchers confirmed the presence of the parasitized bees in New England, and the latest finding indicates the phenomenon is more widespread than previously thought.

The Pennsylvania bees were discovered by Mountain Top beekeeper Sherry Grenzberg, who was sitting at her dining room table when she heard a "plinking" sound against her window from a bee trying to fly toward a chandelier. Having read an article about zombie bees just days earlier, she contacted ZomBee Watch and sent researchers photos and a bee sample. Brian Brown, a phorid fly expert at the Natural History Museum of Los Angeles County, confirmed that the bee was infected by the Apocephalis borealis fly, the parasite behind the zombee infestations. The fly infects a  by depositing its eggs into the bee's abdomen. A few days after the bee dies, fly larvae burst out from between the bee's head and thorax.

"The fly, A. borealis, is common across North America, but this is the first time it has been found to be parasitizing honey bees in the mid-Atlantic region," said Brown, who has studied this group of flies extensively.

"This finding raises questions about whether we might be seeing the early stages of a host shift to honey bees by Apocephalis borealis in the mid-Atlantic region or whether this is something that has gone unnoticed for a number of years," Hafernik said. "Sherry's discovery also emphasizes the important contributions that citizen scientists can make to research on honey bee health, even in a relatively well-studied state like Pennsylvania."

Beekeepers who find their hives are infected should stay calm and use the best beekeeping practices to keep their hives as healthy as possible, as it is most likely that healthy hives are better able to survive infections from the phorid fly or any other pathogen, according to Hafernik. Because researchers are still trying to determine the scope of the zombee infestation, he urged more individuals to join the zombee hunt. The team has developed a series of videos to help new hunters get started.

Grenzberg noted that, as a backyard beekeeper, she can keep a close eye on her hives. "But I have friends who keep their beehives at airports or out in the middle of a farm field, and who knows how many hives they can lose? They could come back in the spring and there are no bees there."

The onset of winter makes it especially important for zombee hunters to make their observations sooner rather than later, particularly in the east, said Hafernik. "There is a window of opportunity right now, but that window is going to close quickly," he said.

Hafernik and his colleagues launched in 2012 to encourage citizen scientists to report cases of parasitized bees, which were first discovered on the SF State campus. Since then, more than 200,000 people have visited the project's website and more than 2,000 zombee hunters have submitted some 600 samples to be tested for infestation. Roughly 25 percent of participants are beekeepers, and the rest are interested citizens doing their part to help track this new threat to honey bee

Read more at:

Invasion of the Zombees: A Bee Horror Movie

Science Friday   October 28, 2014


Up and down the West coast of the U.S., bees are leaving their hives, flying around at night and then suddenly dropping dead. Learn all about the parasitic horror that quietly zombifies these insects and how you can become a real-life zombee hunter.
Produced by Christian Baker 
Additional footage provided by Chris Quock and Dr. John Hafernik 
Music by Audio Network

Learn how you can become a Zombee Hunter!


Apis Newsletter from Malcolm T. Sanford: January 2014

Thank you to Malcolm T. Sanford for his permission to include information from the Apis Newsletter.

This month Dr. Sanford shares with us some of the information he gleaned from the recent American Beekeeping Federation convention in Baton Rouge, Louisiana, home of the Honey Bee Breeding, Genetics, and Physiology Research Laboratory of the U.S. Agricultural Research Service (ARS). He and about 50 members of the convention toured the facility where Dr. John Harbo was among the team of discoverers of what is being called Varroa Sensitive Hygiene (VSH).  The laboratory is also known for its pioneering work in importing Varroa-mite-resistant honey bees into the U.S.  The most important population of these bees occurs in eastern Russia (Primorski region).

Joe Traynor has shared his newsletter with pithy observations for the 2014 pollination season, including  the honey bee research situation in California.

People seem fascinated with zombies, so it's no surprise that honey bees presumably affected by these creatures have been making the blogs on the Internet.  It seems that on the west coast a phorid “zombie” fly Apocephalus borealis is beeing detected with increasing frequency.  Phoridae is a family of flies with a large repertoire of behaviors, mostly as parasites.  Now citizen scientist beekeepers can be on the alert for A. borealis via a web site.  Where this might lead is completely unknown at the moment, but worth keeping one's eyes open.  The saga of the small hive beetle is but one example of unintended, unknown consequences due to a heretofore improbable existence/introduction of an insect species.
View the Archives and Subscribe to the Apis Newsletter 
More about Dr. Malcolm T. Sanford
APIS Information Rescource Center at Squiddo:
Keeping Honeybee by Malcolm T. Sanford and Richard E. Bonney        

Mutant Honey Bees Suffering From Parasitic Strain May Hurt Crops

The Daily Nexus (UCSB) Posted by Aamil Shaik   10/24/12

The Santa Barbara Agricultural Commissioner’s Office recently announced there have been several confirmed sightings of a ‘zombified’ honey bee in downtown Santa Barbara, along with numerous unconfirmed discoveries of the ‘zombees.’

Santa Barbara bees are suffering from a strain of parasite-driven infections, causing the insects to exhibit a number of unusual and potentially crop-killing behaviors such as neglecting their hives, which are vital to local agriculture.

Entomologist Brian Cabrera, who works with the Santa Barbara County Agricultural Commissioner’s Office, said the ‘zombee’ epidemic is the result of an infection from an air-born parasite.

“The bees are zombified because they have been attacked by a parasitic fly. The bee becomes parasitized when a female ‘zombie fly’ lays its eggs inside a bee using a modified structure called an ovipositor,” Cabrera said. “While inside the bee, the eggs hatch out and the zombie fly larvae, which are maggots, begin to consume the contents of the bee.”

According to Cabrera, the insect will begin to display erratic and abnormal behavior as...