Freshwater Insects UK vs the World | Digital Collections

A guest blog by Joseph Deane

In my role as an assistant digitiser, I have been working to transcribe some of the Museum’s freshwater insects. Whilst looking at the labels of these specimens a pattern started to emerge around the types of data being recorded and I wanted to find out more.

We have been digitising the freshwater insect collection by photographing each specimen with our fastest pinned insect digitisation workflow ALICE. ALICE stands for Angled Label Image Capture and Extraction and it enables us to take six simultaneous photographs of the specimen and its labels. This saves time from other workflows as we are not removing the insect from its pin.

Our digitiser Phaedra working to image specimens on ALICE

To transcribe this collection, we look at the images of the labels taken with ALICE and write out this information into the specimen record. The label data will tell us what the specimen is, where and when it was collected and by who. This collection dates back nearly 200 years and this is incredibly important information to understand how biodiversity has changed on earth over this time.

This blog takes a look at the label data from a group of Freshwater Insects. If you want to see the specimens and labels in more detail we have created a dataset for them at

Fab Freshwater Flies

A “Caddis Fly” used for fly fishing based on Caddisflies (Trichoptera)

EPT refers to three orders of freshwater insects: Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies). Part of their life cycle occurs in rivers, ponds and lakes. This makes them important bioindicators, with their presence and population size able to give an indication of the health of the freshwater habitats they live in. This collection is being digitised as part of the SYNTHESYS+ Virtual Access funded project to better understand the size and distribution of these groups. The data from this project being used by the International Union for Conservation of Nature (IUCN) to red list species at risk of extinction and help with conservation efforts. You can read more about the project in our previous blog.

The Museum’s EPT collection contains ~75,000 specimens with ~65,000 of those being pinned, including 1,700 types (the example specimen after which a species was named). These collections represent over 4,000 species, collected from 112 countries, with the oldest specimen being from 1830.

Ephemeroptera (Mayflies) are the most well-known group due to their short adult life spans, which can be as short as a few hours. Though this is because most of their life is spent as aquatic larva. This is true of all three orders of freshwater insects. Plecoptera (Stoneflies) translates to braided-wings, referring to the pattern of the veins of their wings. Trichoptera (Caddisflies) are very moth like in their appearance, their name referring to their hairy wings. They are unique among EPT as most, but not all members have larva that build cases out of items they find in their environment (e.g. stones, leaves or shells). The caddis larvae live in these tubes till they pupate into adults and emerge from the water.

These orders were relatively well collected, with fly fishing lures being modelled after these members of these orders. Making it a popular group for both amateur collectors and professional entomologists to work on.

British Labels

While transcribing some of the specimens from mid-20th century, I started to notice that British labels often lacked a country instead starting with a region of the UK as the highest geographical marker such as Oxford, York, or Essex. As there is limited space on the label this allowed the label much more detail with the exact villages or streams these specimens came from able to be written down. International labels on the other hand often just stated the country or region the specimen has been taken from.

These two specimens collected by Martin E. Mosely, both have detailed information of where they were collected but the French specimen explicitly states France on it where the UK specimen does not state a country at all, instead only showing the region of the UK (in this case Derbyshire).

The Collector Network

While more modern parts of collections may have been informed by the scientists working on them today, in the past there was less standardisation around the types of information that should be recorded by collectors. Older specimens were collected without this knowledge and contain the data that the collector themselves found most useful.

“Many Museum curators had wide networks of other researchers they sent material to and received specimens from” – Dr Ben Price Senior Curator of Small Orders.

Two of the main collectors that have been cropping up in this collection have been Martin E. Mosely and Robert McLachlan. Martin Ephraim Mosely was a key collector of EPT specimens despite originally being banker with a keen interest in fly fishing collecting only as an amateur in his free time. When he retired at 52, he joined the Museum as an unofficial scientific worker with his own large collection of over 7,000 Trichoptera becoming part of the Museum’s collection upon his death in 1948.

Mosely studied the work of Robert McLachlan, a key entomologist in the 19th Century. McLachlan specialised in Trichoptera later in life until his death in 1904. McLachlan’s large insect collection was purchased by The Museum in 1938 and contained over 50,000 specimens including 12,750 Odonata (Dragonflies and Damselflies), 14,000 Trichoptera and 500 type specimens. Type specimen being the one that holds the species name and was used to first describe the species scientifically. Although they never met, Mosely based his style of working on McLachlan. This could be said to be the beginning on the stardardistation of the EPT collection.

Mosely and McLachlan are not the only collectors that make up the Museum’s EPT collection. Other collectors such as Frederick Chapman, Rev. Laurence Grensted and William Fassnidge all show similar patterns in their labels and all are British. Douglas Eric Kimmins and William Edward China were two collectors often found together on specimen labels. Both worked at the museum together with Kimmins having trained under Mosely.

Great British Bias?

The UK collection within EPT makes up a significant portion of the total 75,000 specimens (roughly a quarter). The rest of the collection representing those found outside of the UK which includes the majority of EPT species. With only 290 species of EPT native to the UK compared to the over 4,000 present in the collection. This means that now, the international parts of our collection are more valuable as they are much less understood and could give greater insight into these species, with this being a particular focus of the EPT project.

Many UK collectors such as Mosely and McLachlan also went to other countries and collected samples to bring back and study. Looking at who originally wrote these labels and with what audience in mind, can give us a better understanding of the pattern we are finding.

A British audience may not need to be told Oxford or Southampton were in England, this assumed knowledge left off the label, but they may need to be told locations in France, Sweden, or Switzerland. As we did not start mass digitising the collection until 2014, the people studying the collection would have been in the UK to visit the Museum and its specimens.

The information recorded by these collectors can be very precise within the UK, naming exact villages and even the exact stream this freshwater insect was collected from. Many non-European labels (often still collected by European collectors) are even more vague about locality of collection.

The lack of clear data has an impact on how accurately these specimens can be transcribed. When the digitisation team are transcribing label data into our collections management system, we are only able to add country level information when we have enough data to do so, if we cannot say for certain which country a specimen is from, we must leave it as unknown. Many British specimens had to have country level information added because it had been left out for the assumed obviousness of it in a British collection. However, this can be an issue when looking at non-European specimens due to a lack of information on these labels compared to the UK and European specimens making an accurate country identification much harder or impossible having to leave this as unknown.

Looking to the Future

Close up of an insect inside ALICE

Science is increasingly more collaborative on a global scale with papers, findings, and information shared in a way not possible in the 19th and early 20th century. We know through tracking onward use of the Museum’s entire digital collection we have seen 30 billion records downloaded over 490,000 download events and over 1,700 scientific papers cite our digital collection on topics from biodiversity, conservation, human health, and climate change. The potential use for Museum data is constantly expanding with developments in technology such as computer vision and optical character recognition. We can only hope that in the future our data is being used for things we cannot even imagine today.

Global researchers at the International Union for Conserving Nature using the specimens to understand risk of extinction for these species, something 19th and early 20th century collectors would never have thought possible.

“We find more and more ways of using the specimens and their data, way beyond the wildest dreams of the original collectors.” – Dr Ben Price Senior Curator of Small Orders.

I have really enjoyed getting the chance to work in the digitisation team for my Kickstart placement. I have learnt how to handle and digitise a range of natural history specimens and now also have a much deeper appreciation of how important the label data is on the specimens in the collection. If you want to see more detail on the specimens and data referred to in the blog please check out this dataset on the Museum’s Data Portal.