Can we survive without bees, the chief pollinator?
The great Albert Einstein, although disputed by some, is often quoted to have famously stated that if there were no bees around any more, humans would have only 4 years to survive. Whether or not he actually had made such a statement, these days honey bees are very much in the news as reports of a decline in bee populations come in from various parts of the world.
Parasites like the destructive Varroa mite, irresponsible uses of pesticides, Nosema, viral and other diseases, climate change, over-domestication and many other factors have been held responsible for this well publicised dying-off of the bees – and dire consequences for the global food production have been predicted. It puzzles me, however, because for the past 4 and a half years I have been living on the Japanese island of Hachijojima, which does not have honey bees, but boasts of a successful fruit production: lemons, passion fruit, melons and others. Sure, some veges are imported from mainland Japan, but for centuries the islanders have produced sufficient food without bees.
Fact is that worldwide more than 80% of our crops depend on insect pollinators and of the latter, which include beetles, flies, butterflies and many other insects, honey bees are by far the most important ones. The 20% remainder of our plant-based foods are pollinated by wind or are self-pollinating. So, what about my island Hachijojima then? On that island people replace bees and that works (at least on Hachijojima) quite well: melon flowers are touched with a little brush and the latter, carrying adhering pollen grains, is then manually dipped into other melon flowers. The passionfruit horticulturist takes a flower and touches with it as many other flowers he can reach, basically ‘playing to be a bee’. And it works as the harvest of tasty passionfruit later in the season demonstrates. The enormous numbers of lemons produced on Hachijojima also do not depend on bees: a draught of wind is created in the long greenhouses full of lemon trees by opening the doors on either side. Bees are not necessary. And I’ve seen places where strawberries are grown in long transparent plastic ‘tunnels’ (not on Hachijojima though) and flies are sent into the tunnel to pollinate the berries quite efficiently. So, are the doomsayers predicting tremendous crop and food reductions as a consequence of the bee decline correct? Probably only partially so, for a publication in the journal Current Biology by M.A. Aizen et al. in which yields of crops that do and do not require pollinators were compared with each other found no differences were apparent.
And yet, the situation is almost certainly more complicated when we consider the nutritional value of a crop, for according to a recent 2018 study by Ghosh and Jung it’s pollinator-dependent (PD) crops that provide a greater share than do crops that are considered non-pollinator dependent (NPD) when it comes to the content of the nutritionally important minerals and vitamins C and E as well. Their results were meant to demonstrate the importance of pollination, but if according to Aizen et al. (see above) pollinator-dependent crops have not decreased despite the apparently alarming decline of pollinating bees, what is happening? Do pollinators other than bees fill the empty niche, are humans with little brushes like on Hachijojima ‘replacing’ bees, or are pollinator-dependent crops not really as pollinator-dependent as thought? It’s confusing like many other food-related statements and recommendations nowadays. But I like apples and honey too and for that reason alone (how selfish!) I hope the global bee decline can be stopped.
© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2019.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.