Image of the Week: Varroa Parasitic Mite

This week’s image is of the little mite that might cause the end of food production as we know it. The varroa parasitic mite attacks the honey bee populations needed to pollinate a range of valuable crops including sunflowers, almonds and tomatoes. After attaching itself to the underside of the bee, the mite sucks the hemolymph, a substance that surrounds all the bees’s cells.

It is only possible to see this varroa mite so clearly because the image was created using a scanning electron microscope. Verroa mites are actually only 1.5mm by 1mm making them almost impossible to see on a live adult bee. In reality this mite would also be a red brown colour providing camouflage against the surface of its victim. All images created with a scanning electron microscope are originally colourless, and in this image the purple and green colouring was added later to help us see the mite more clearly.

Unfortunately, there doesn’t appear to be a simple way to save our humble honey bee. The mysterious and alarming increase in bee deaths over the past decade is caused by several factors. Pesticides and a lack of nutrition due to farming practices and the spread of verroa mites have all contributed to the decline of the honey bee population.

Since bees are vital to ensuring plants are pollinated, a decline in their numbers could have devastating effects. In China, some farmers have resorted to hand pollinating their fruit trees, painstakingly collecting, drying and then reapplying pollen to individual flowers. Unsurprisingly this method is no match for the bees, as a single bee can visit more than a hundred flowers in a single flight!

This week’s image reminds us of how very small things can have a big effect and shows how much we depend on the complex biological systems that surround us.

Image credit: Kevin Mackenzie, University of Aberdeen and Wellcome Images, London

Wellcome Images is one of the world’s richest and most unusual collections, with themes ranging from medical and social history to contemporary healthcare and biomedical science. All our images are available in digital form and many are free to use non-commercially under the terms of a Creative Commons licence.