A team from our Institute has studied the use of UV light in the digitization of natural history collections. UV light reveals fluorescent parts of specimens. Not only does a low cost UV light setup make for more detailed pictures, it can also provide taxonomists with more possibilities for new research.

Follow the links in the last paragraph to discover the secrets different species show under UV light!

When digitizing specimens from natural history collections – with detailed photographs or 3D models – researchers do their best to capture the insect, flower, fossil, ... with the highest possible detail. Human sight, however, is not perfect: the ultraviolet and the infrared spectra are out of our reach. This in contrary to rats, insects and spiders, that can see ultraviolet, or some snakes, that perceive infrared. In other words: there are secrets that remain hidden if we only rely on our own sight.

That is why researchers from our Institute and the Royal Museum for Central Africa tried out the effects of UV exposure when photographing collection items. Given that many specimens react to UV light in the form of fluorescence, there are a lot of morphologic characteristics that remain hidden to the naked eye. For example: UV light can help taxonomists – scientists that describe and species and define biological groups – distinguish between male and female in some species.

The team also found that exposure to UV light in different wavelengths, in combination with a low cost focus stacking setup increases the detail of the picture. The disturbed colours as a result of the UV light can be overcome by adding filters or converting the image into greyscale.

But they also give the specimens a magical effect! Take a look at what UV light does to the detail in the wing of this Dictyophorus griseus, a species of grasshopper. The UV light also enhances the beautiful green colour of this Neoharisea sp, a stick insect. The hairs and different part of the legs become much more visible in this Solpugema hostiles, a species of camel spider, and the abdomen of the Storena formosa shows a lot more detail under the influence of UV light.

“While there are lots of species that fluoresce, you are never sure in which way they will react under UV light. But it is always a pleasant surprise”, concludes Jonathan Brecko (RBINS, RMCA), who led the study.

The research article appeared in PLOS ONE.