The bees have had it bad for some time now. But the latest blow was dealt directly by mankind, scientists say.
Global bee populations have been hit increasingly hard by the spread of Varroa destructor mite, which researchers have linked to "colony collapse disorder" that is devastating honey bee populations around the globe.
The decline of bee populations could have severe ecological and economic consequences. Plant populations generally suffer as a result of colony collapse – some depend entirely on honey bees to produce fruit. Moreover, honey bees are the primary pollinators of most human food crops. Without them, global food production could experience a drastic collapse.
Researchers found that the vast majority of infected hives, regardless of geographic location, could be traced back to one source – Apis mellifera, the European honey bee. The study, which was led by University of Exeter scientists, appeared Thursday in the journal Science.
If Varroa were spreading naturally, transmission would occur between countries that are geographically close. But researchers found that New Zealand’s infected population, for example, originated in Europe. In other words, the international shipment of non-native bee colonies has hastened the effects of colony collapse on a global scale.
"Bees, and especially queen bees, are traded as a commodity to improve stock quality or to start up new colonies," lead author Lena Bayer-Wilfert says. "Whole hives have also been moved as part of a kind of developmental aid – this is actually a great thing, but historically has contributed to the rapid spread of Varroa."
"We will not be able to eliminate Varroa or introduce resistant honey bees at a short time scale, but constant control of Varroa and good beekeeping practices will limit the negative effects and the spread of these diseases between honey bees and to wild pollinators," Dr. Bayer-Wilfert says.
"At a larger scale, the international regulations on honey bee movements should be maintained and adhered to. This is not a case of ‘Well, the genie is out of the bottle now…’ This work really highlights the risks we incur when moving animals and plants outside their native ranges."