They may explain the mystery of bee disappearance

in late 2006, a third of all bee colonies in North America saw their worker bees disappear. Scientists called this abnormality colony collapse disorder, or ccd. It hit hard industries dependent on honeybees, and its cause is not yet established.

Everything from the Varroa mite and viruses to pesticides and malnutrition has been blamed. Recent studies even explored the effects of radiation and mobile network signals.

Now American scientists have analyzed the genetic content of one of the suspects, the fungal parasite Nosema cerana. This fungus was first identified as a pathogen in honeybees (Apis mellifera) in 2004. It had earlier been detected in the oriental bee species, Apis cerana.

R Scott Cornman of the US Department of Agriculture and his colleagues first isolated the parasite spores from the alimentary tract of the dead bees. Then they extracted spores