ZomBee Watch is a citizen science project sponsored by the San Francisco State University Department of Biology, the San Francisco State University Center for Computing for Life Sciences and the Natural History Museum of LA County. ZomBee Watch was initiated as a follow-up to the discovery that the Zombie Fly Apocephalus borealis is parasitizing honey bees in California and possibly other areas of North America. You can read or download a copy of our original scientific paper, A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis, for free from PLoS One.

Honey bees infected by the Zombie Fly leave their hives at night and are attracted to nearby lights where they become stranded and eventually die. The presence of fly larvae in up to 18% of active foragers in some California honey bee hives makes the Zombie Fly a potential contributor to hive declines. This would be especially likely if Zombie Fly infection is widespread and higher in areas that are experiencing hive declines. We founded ZomBee Watch to find out how widespread Zombie Fly parasitism is and to learn how often unparasitized honey bees are attracted to lights at night for other reasons.

There are many ways you can get involved. It can be as easy as collecting honey bees that are under your porch light in the morning, under a street light or stranded on sidewalks. If you are a beekeeper, setting up a light trap near one of your hives is the most effective way to detect ZomBees. It's easy to make a simple, inexpensive light trap from materials available at your local hardware store. To test for the presence of Zombie Fly infection all you need to do is put honey bees you collect in a container and observe them periodically. Infected honey bees give rise to brown pill-like fly pupae in about a week and to adult flies a few weeks later. View the tutorial.

A ZomBee and four emerged pupae

In California, parasitism begins to increase in early June and peaks in the fall and early winter months. Most records of the fly from other parts of North America (such as the Midwest and Northeast) are from late May to September, which is the most likely time that parasitism will be observed by citizen scientists in those areas.

Not all honey bees attracted to light produce Zombie Fly pupae. Whether or not you find parasitized bees, we are interested in your records.

A male Zombie Fly

Abandoning hives is one of the symptoms of Colony Collapse Disorder (CCD) an unexplained threat to honey bees. Understanding what's going on in the case of "ZomBees" could help in understanding what causes CCD.

A female Zombie Fly A female Zombie Fly. Notice her ovipositor at the end of her abdomen that is used for laying eggs inside a bee.

You may have heard that phorids that parasitize introduced fire ants have been released into the US as a biocontrol agent for the ants. The fire ant phorids are specific to fire ants and do not parasitize honey bees. Read about USDA's use of Phorid Flies as Biocontrol Agents. A very common species of phorid, Megascelia scalaris, feeds on all kinds of decaying matter including dead honey bees. Because of this, It is sometimes mistaken for the Zombie Fly. You can find out more about phorids at Phorid.net (http://www.phorid.net/).

A female Scuttle fly Megascelia scalaris (source: www.phorid.net)

Like all flies, butterflies and many other insects, Zombie Flies undergo complete metamorphosis as they mature. The begin life as an egg that hatches into a larva (maggot). The Maggots begin feeding within a live honey bee. After the maggots grow for a number of days, an infected honey bee abandons its hive during the night and dies away from the hive , Once the maggots finish eating the insides of the now dead bee, they exit the bee and form pupae (the equivalent of butterfly chrysalids) away from the bee. As many as 15 maggots may come out of a single honey bee. In two to four weeks the pupae hatch into adult flies beginning the cycle again.

In California, parasitism begins to increase in early June and peaks in the fall and early winter months. Most records of the fly from other parts of North America are from late May to September.