Christmas presents summarised: great fun, often panic-inducing, delivered by Santa, rife with socks and an integral part of Christmas for most. However given that gifts play such a large role in the festive season, it is astonishing how little attention we pay to the undeniably best gift at Christmas time: FOOD, and lots of it!

Everyone enjoys the cheerful chow that starts flooding into our lives at this time of the year-the odd hot mince pie here, a roasted chestnut there - but often we indulge without realising who we really owe it to.

Well, the unsung heroes of Christmas nosh are a group of generous and diligent animals, and they are not reindeer! Move aside Rudolph and enter a multitude of small, diverse, six-legged creatures… the pollinating insects. Given their scarcity in winter months, insects might seem a surprising animal group to associate with Christmas. However it is the job they do in the spring and summer, delivering pollen between the flowers of crops and wild plants thus allowing their fertilization, that is key to our Christmas menu.

Every item in your traditional Christmas dinner is dependent (directly or indirectly) on the pollinating services of insects. These insects include the more obvious honey bees and bumblebees, as well as solitary bees, hoverflies, wasps, beetles and thrips (1). Increasingly, commercial crop production relies heavily on managed honey bee colonies. A study of crop pollinators in the U.S. found that onions and carrots are 100% reliant on insect pollinators, 90% of which are honeybees (2). Parsnips, Brussels sprouts and cranberries also all require bees specifically for commercial growing (3),while a wider range of insects pollinate potatoes* and red cabbage (4) (3).

It’s not only vegetables which rely on insect pollination. The Christmassy ingredients that make up stuffing, bread sauce, mince pies and mulled wine, such as cloves, sage, nutmeg, chestnuts, cherries, oranges, currants and chocolate would all be sacrificed without the services of insects (3). Even the turkey is likely to have been fattened on insect-pollinated feed, such as soybeans (10% of the production of which is reliant on insects) (2). Dairy products, required for brandy butter and bread sauce, rely indirectly on wild insects because dairy cows are fed on clovers and trefoils which, for example, bumblebees very efficiently pollinate (5). Then there is the good old figgy pudding, star-at-large of Christmas carols. All figs are pollinated by fig wasps, with most figs having a specific wasp species which exclusively pollinates it (6).

Therefore it is clear that if we cut out pollinators, we can cut our Christmas dinner.

Pollinators in the UK are declining, with dire consequences for food production, the economy, and our native biodiversity. Drivers to declines include land use changes, agricultural intensification, pesticide poisoning, habitat loss and disease. 72% of butterfly species are declining (7), 25% of European honey bee colonies have been lost recently (8), and wild bees are dwindling, with 2 bumblebee extinctions in the last half century (9).

This Christmas, while you are relishing the delicious yet controversial Brussels sprouts, or the sweetness of the blob of cranberry sauce on your turkey, spare a thought for the pollinating insects (now tucked away overwintering), which made it possible.

References

1. The importance of pollinators in changing landscapes for world crops. al, Klein et. 2007, Proceedings of the Royal Society.

2. The Value of Honey Bees as Pollinators of U.S. Crops in 2000. R.A. Morse, N.W. Calderone. s.l. : Cornell University, 2000.

3. Diana Sammataro, Alphonse Avitabile and Dewey M. Caron. The Beekeeper's handbook. s.l. : Cornell University Press, 2011.

4. Insect Pollination of Cultivated Crop Plants (online pollinator handbook). McGregor, S.E. 1976.

5. [Online] http://www.pollinator.ca/canpolin/clover.html.

6. Co-evoluation of figs and their insect pollinators. J.T.Wiebes. s.l. : Annual Reviews, 1979, Annual review of ecology and systematics, Vol. 10, pp. 1-12.

7. The State of the UK's Butterflies. Fox, R,. Brereton, T.M., Asher, J., Botham, M.S., Middlebrook, I., Roy, D.B. and Warren, M.S. Wareham : Butterfly Conservation and the Centre for Ecology and Hydrology, 2011.

8. Declines of managed honeybees and beekeepers in Europe? Potts, S.G. et al. 49, s.l. : Journal of Apicultural Research, 2010.

9. Decline and conservation of bumblebees. Goulson, D. et al. s.l. : Annual Review of Entomology, 2008.