Preparing Lepidoptera for Digitisation | Digital Collections Programme

We are working to digitise more than half a million British and Irish butterflies and moths. Our three year iCollections project started in 2013, and we have received additional funding from the Cockayne Trust to continue this digitisation work to September 2017.

Photograph from above of a drawer filled with vertical columns of the butterflies pinned to the base, with paper labels in the top and bottom left, and the bottom right.
Original drawer with Mullein (Cuculblia verbasci) specimens.

The mass digitisation of this collection has given Museum scientists the opportunity to study these specimens in new ways. In addition to research carried out in the Museum, digitisation also allows anyone around the world to see the specimens via the Data Portal.

Hidden Gems

In digitising Lepidoptera, we have developed and perfected new techniques which can be directly applied to other pinned insect collections within the Museum. We also have been unlocking unique historical memories from the specimens themselves.

Due to the way in which most butterflies and moths are set after pinning, it’s not always easy or possible to read what is written on the labels beneath the specimen; indeed some collectors made it particularly difficult; purposefully turning over labels so that nothing could be read by looking at specimens in a drawer (possibly in order that their contemporaries wouldn’t get wind of a particularly good collecting site for less common species).

This means that when we prepare specimens for digitisation, we  find out some fascinating stories, which give real context to the collection and provide light hearted and enlightening moments. As we enjoy these stories so much we have started using #MothMonday to post some of these images and stories on twitter.


Preparation begins by heading down to the British and Irish collection to bring species back to the digitisation area. These specimens are housed in older, cork-lined drawers. As the cork lining ages, it dries out and contracts around the pin. This means we have to be very careful not to damage these fragile specimens as we remove them. To enable us to access label data, we remove the labels from the pin.

This can be a fiddly task made even trickier due to the majority of the British and Irish Lepidoptera collection being on short pins, with little space to get forceps in and tease the labels off the pin! We lay the labels out with the specimen, in a specially designed unit tray that has a raised level at the side.

Photo showing a specimen being moved using a pair of forceps clasping the top of the pin
Close-up of a small yellow underwing (Panemeria tenebrata)

This enables the labels to be brought up to the height to the specimen, making it easier to capture a high resolution image with focus on the specimen and label simultaneously. The unit trays also contain a scale bar to provide measurements. They are lined with a neutral, grey plastazote, enabling us get the lighting and colours spot on when we image the specimens.

We place the labels inside the unit tray so that the chronological order in which they were put on the specimen is preserved.  Then, we add a unique number to every specimen – on this label there’s also a data matrix (basically a barcode) encoded with the specimen number – and then finally this last label is placed in the unit tray and into a conveyor drawer. From here we then go on to image the specimens, and transcribe the labels into a database.

Photograph showing a 4 by 4 grid of drawers, each containing a specimen, ruler, QR code and text based labels. The bottom left drawer also includes the Type specimen with its labels
Panemeria tenebrata unit trays in a conveyor drawer

To complete the Cockayne Project, we will need to conduct this process about another 170,000 times.  Fortunately, since we started the project at the beginning of April this year, we’ve already digitised around 70,000 specimens. As we digitise on average 600 specimens a day (though our record is 1,008), we’ve got our work cut out!

If you enjoyed reading this, please follow us on twitter for regular #mothmonday updates.  We would love to hear your Lepidoptera stories and what you want to hear about us so please tag @NHM_Digitise with your photos or comments!

Peter Wing
Digitiser, Lepidoptera

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