accounted for a loss of 22% of the U.S. bee colonies during the winter of 2007-2008
large bee losses were reported in Australia, Brazil, Canada, China, & Europe. ⅓ of
world's agricultural production depends upon Apis mellifera - European honeybee -
for armies crop pollinators at almost any time of the year.
Several potential causes, working together may be the cause of colony collapse including:
varroa mites - a parasite that sucks hemolymph
nosema apis - a single celled fungal parasite that causes bee dysentery
new synthetic poison - as acaricides (neonicotinoids: act like nicotine) used to kill mites
tobacco plants deploy nicotine against leaf-eating pests & could enter pollen.
subsequent analyses have discovered over 170 different chemicals (some 35 in pollen).
poor nutrition - fewer natural food sources could lead to diseases of honey bees
all these are opportunistic infections possible caused by a weakened bee immune system.
Using metagenomics (all nucleic acids of environ are collected and sequenced): the organisms
present are then identified - revealing a never before identified virus in U.S. bees -
IAPV - Israeli acute paralysis virus (1st identified in 2004).
Healthy bees exposed to IAPV mimicked the CCD symptoms and dies away from hives.
Consensus is that multiple factors - poor nutrition, pesticide exposure, & parasites-
weaken colonies and make them susceptible to virus mediated collapse.