{"id":16760,"date":"2012-01-09T12:00:37","date_gmt":"2012-01-09T12:00:37","guid":{"rendered":"http:\/\/www.transcend.org\/tms\/?p=16760"},"modified":"2012-01-09T12:16:48","modified_gmt":"2012-01-09T12:16:48","slug":"zombie-fly-parasite-killing-honeybees","status":"publish","type":"post","link":"https:\/\/www.transcend.org\/tms\/2012\/01\/zombie-fly-parasite-killing-honeybees\/","title":{"rendered":"\u201cZombie\u201d Fly Parasite Killing Honeybees"},"content":{"rendered":"

A heap of dead bees<\/a> was supposed to become food for a newly captured praying mantis. Instead, the pile ended up revealing a previously unrecognized suspect in colony collapse disorder\u2014a mysterious condition that for several years has been causing declines in U.S. honeybee populations, which are needed to pollinate many important crops. This new potential culprit is a bizarre\u2014and potentially devastating\u2014parasitic fly that has been taking over the bodies of honeybees (Apis mellifera<\/em>) in Northern California.<\/p>\n

John Hafernik, a biology professor at San Francisco State University, had collected some belly-up bees from the ground underneath lights around the University\u2019s biology building. \u201cBut being an absent-minded professor,\u201d he noted in a prepared statement, \u201cI left them in a vial on my desk and forgot about them.\u201d He soon got a shock. \u201cThe next time I looked at the vial, there were all these fly pupae surrounding the bees,\u201d he said. A fly (Apocephalus borealis<\/em>) had inserted its eggs into the bees, using their bodies as a home for its developing larvae. And the invaders had somehow led the bees from their hives to their deaths. A detailed description of the newly documented relationship was published online Tuesday in PLoS ONE<\/em><\/a>.<\/p>\n

The team performed a genetic analysis of the fly and found that it is the same species that has previously been documented to parasitize bumblebee as well as paper wasp populations. That this parasite hasn\u2019t previously been reported as a honeybee killer<\/a> came as a surprise, given that \u201choneybees are among the best-studied insects of the world,\u201d Hafernik said. \u201cWe would expect that if this has been a long-term parasite of honeybees, we would have noticed.\u201d<\/p>\n

The team found evidence of the fly in 77 percent of the hives they sampled in the Bay Area of California, as well as in some hives in the state\u2019s agricultural Central Valley and in South Dakota. Previous research has found evidence that mites, a virus<\/a>, a fungus, or a combination of these factors \u00a0might be responsible for the widespread colony collapse. (Read more about colony collapse disorder in our feature \u201cSolving the Mystery of the Vanishing Bees<\/a>.\u201d) And with the discovery that this parasitic fly has been quietly killing bees in at least three areas, it might join the list of possible forces behind colony collapse disorder.<\/p>\n

The parasitic fly lays eggs in a bee\u2019s abdomen. Several days later, the parasitized bee bumbles out of the hives\u2014often at night\u2014on a solo <\/strong>mission to nowhere. These bees often fly toward light and wind up unable to control their own bodies. After a bee dies, as many as 13 fly larvae crawl out from the bee\u2019s neck. The bees\u2019 behavior seems similar to that of ants that are parasitized\u2014and then decapitated from within\u2014by other fly larvae from the Apocephalus<\/em> genus.<\/p>\n

\u201cWhen we observed the bees for some time\u2014the ones that were alive\u2014we found that they walked in circles, often with no sense of direction,\u201d Andrew Core, a graduate student who works with Hafernik and a co-author on the new paper, said in a prepared statement, describing them as behaving \u201csomething like a zombie.\u201d (Read about other parasites that turn their hosts into zombies in the article \u201cZombie Creatures<\/a>.\u201d)<\/p>\n

Bees from affected hives\u2014and the parasitizing flies and their larvae\u2014curiously also contained genetic traces of Nosema ceranae<\/em>, another parasite, as well as a virus that leads to deformed wings\u2014which had already been implicated in colony collapse disorder. This double infection suggests that the flies might even be spreading these additional hive-weakening factors.<\/p>\n

The research team plans to track bees with radio tags and video cameras to see whether infected bees are leaving the hive willingly or getting kicked out in the middle of the night\u2014and where the flies are finding the bees in which they lay their eggs. \u201cWe assume it\u2019s while the bees are out foraging because we don\u2019t see the flies hanging around the bee hives,\u201d Hafernik said. \u201cBut it\u2019s still a bit of a black hole in terms of where it\u2019s actually happening.\u201d Most of the parasitized bees found so far have been foraging worker bees, but even if other groups of bees within a hive are not becoming infected, a decline in the number of foragers in a hive could have a large impact on a hive as a whole. Models of colony dynamics suggest that \u201csignificant loss of foragers could cause rapid population decline and colony collapse,\u201d the researchers noted in their paper.<\/p>\n

Hafernik and his colleagues hope that the simple way they made their discovery \u201cwill enable professional and amateur beekeepers<\/a> to collect vital samples of bees that leave the hive at night\u201d\u2014with a light trap, for instance\u2014and keep them around for a week or so to observe for any signs of emerging larvae. Pinpointing the extent of this strange bee behavior could be key to stemming colony collapse disorder by possibly allowing keepers to isolate affected populations. If the parasitic fly is just starting to infect honeybee populations, this could be an important move, especially given the newly prevalent mobile commercial hives<\/a>, which mean that honeybees\u2014and their ailments\u2013are on the move in much greater numbers than ever before.<\/p>\n

__________________________<\/p>\n

Katherine Harmon is an associate editor for Scientific American covering health, medicine, and life sciences. Before joining the online team, she received her master’s degree from the University of Missouri School of Journalism. Her award-winning work has appeared in newspapers, magazines and websites.<\/em><\/p>\n

Go to Original \u2013 scientificamerican.com<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

John Hafernik, a biology professor at San Francisco State University, collected some belly-up bees from the ground around the University\u2019s biology building. \u201cBut I left them in a vial on my desk and forgot about them. The next time I looked at the vial, there were all these fly pupae surrounding the bees,\u201d he said. A fly (Apocephalus borealis) had inserted its eggs into the bees, using their bodies as a home for its developing larvae. And the invaders had somehow led the bees from their hives to their deaths.<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[61],"tags":[],"class_list":["post-16760","post","type-post","status-publish","format-standard","hentry","category-environment"],"_links":{"self":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/posts\/16760","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/comments?post=16760"}],"version-history":[{"count":0,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/posts\/16760\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/media?parent=16760"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/categories?post=16760"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/tags?post=16760"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}