News Release

NHM entomologist co-authors new research on parasitic phorid fly, a new threat to honey bees

Understanding infections from flies may shed light on bee colonies' hive abandonment behaviors seen in Colony Collapse Disorder

Peer-Reviewed Publication

Natural History Museum of Los Angeles County

Images of <i>Apocephalus borealis</i> and Honey Bees

image: These are images of <i>Apocephalus borealis</i> and honey bees. (A) Adult female <i>A. borealis</i>. (B) Female <i>A. borealis</i> ovipositing into the abdomen of a worker honey bee. (C) Two final larvae of <i>A. borealis </i>exiting a honey bee worker at the junction of the head and thorax (red arrows). view more 

Credit: Natural History Museum of Los Angeles County

Jan. 2, 2012 – A paper to be published on January 3, 2012 in the authoritative magazine PLoS ONE, co-authored by NHM entomologist Dr. Brian Brown, reveals a new threat to honey bees and perhaps, a partial explanation for the bees' well-publicized Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. The threat is the tiny but dangerous phorid fly, which may pose an emerging threat to North American beekeeping.

The honey bee Apis mellifera has experienced recent unexplained die-offs around the world. Although catastrophic losses of honey bee colonies have occurred in the past, the magnitude and speed of recent hive losses appear unprecedented. So far, the main causal suspects have been parasitic mites, fungal parasites, viral diseases and interactions amongst them.

In this paper, the authors provide the first documentation that the phorid fly Apocephalus borealis, previously known to only parasitize bumble bees, also infects and eventually kills honey bees — by leading them to abandon their hives at night.

Brown is a world authority on phorid flies, and blogs about the weird creatures at He has received reports of nighttime bee activity in Los Angeles. "It seems to be concentrated near the coast," he said, "which is where our collecting has also encountered the flies."

The authors prove that parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later, up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, the authors confirmed that phorids that emerged from honey bees and bumble bees were the same species.

Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD. Further, knowledge of this parasite could help prevent its spread into regions of the world where naïve hosts may be easily susceptible to attack.


In addition to Brown, the paper's authors include Andrew Core, Charles Runckel, Jonathan Ivers, Christopher Quock, Travis Siapno, Seraphina DeNault, Joseph DeRisi, and John Hafernik from the San Francisco State University.

About the NHM Research and Collections:

Natural history museums are powerhouses of research. As the last bastions of taxonomy — in which new species and families are described, and thought is given to how the old and new fit together — museums provide the brick and mortar of all biodiversity research.

At NHM, curators and collections staffs are widely-recognized authorities in their fields. They win major grants. They serve as faculty and research associates at universities, museums and other institutions, and publish regularly in journals and magazines. They are engaged in field and onsite research, teaching, and public speaking. They also preserve and strengthen the Museum's collections — the platform upon which exhibitions, public programs and membership are built.

About the Entomology Department:

With over 800,000 described species — more than half of all known living organisms — insects are the most diverse group of animals on Earth. The Museum's entomology collection has more than 5.8 million specimens of insects and spiders. It is the largest in Southern California and has specimens from all over the world.

The collection's strength lies in its holdings of specimens of ants, phorid flies, scarab beetles, and moths from North and Central America. Museum scientists conduct world-class research on systematics, studying species and their relationships, the evolution of major groups, and fossil insects in amber. They conduct field work on insect biodiversity at home and in tropical countries. Entomology was one of the Museum's founding departments, dating back to the institution's opening in 1913.

About the Natural History Museum of Los Angeles County:

The Natural History Museum of Los Angeles County is at 900 Exposition Blvd., Los Angeles, CA 90007. Open seven days a week 9:30 a.m.-5 p.m. Tickets $12 for adults, $5-8 for children. Admission is free the first Tuesday of every month. For more information, call 213-763-DINO or visit

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