Researchers say the already-threatened honeybee is now under attack by tiny flies that cause the bees to turn into zombie-like creatures that stagger around at night before actually succumbing to death.

Honeybees are disappearing all over the country as vampire mites and nutritional deficiencies have led to bee colonies dying out in recent years, and the zombie bee cases, a West-coast phenomenon for some time, appears to be spreading east, according to an article on foxnews.com.

Scientists believe the Apocephalus borealis fly attacks the honeybees while they are feeding, depositing eggs into the abdomen of the bee and eventually affecting the way the doomed bees behave.

Although the fly had been known to attack bumblebees and yellow jackets in the past, it wasn’t until 2008 that John Hafernik, a biology professor at San Francisco State University, noticed bees that appeared to be disoriented around a light outside his office on the campus.

After collecting some of the bees for further study, he began to notice pupae coming out of a bee.  After that, there were many more reported cases of honeybee infections around the San Francisco area and surrounding areas.

In 2012, Hafernik started a project, called ZomBee Watch, designed to recruit people to look for and document cases of the fly invasion, and to upload photos of the pupae and/or the adult flies emerging from the bees.  Thus far, more than 100 confirmed cases have been documented.

The first confirmed case in the Eastern united States was in 2013, when a beekeeper in Burlington, Vermont, noticed bees behaving like zombies.  This past summer, two more cases of the infection were confirmed in the Hudson Valley, north of New York City.

Hafernik said, “We’re not making a case that this is the doomsday bug for bees.  But it is certainly an interesting situation where we have a parasite that seems to affect the behavior of bees and has them essentially abandoning their hive.”