Moth collected by Alfred Russell Wallace rediscovered and helps to describe 11 new species

Consisting of just a thorax and a couple of wings, you’d be forgiven for thinking that a 1.2-centimetre-long off-white moth in the depths of the Natural History Museum’s collections is past its prime.

This was certainly the opinion of Edward Meyrick, the world expert on this group of moths, who in 1927 recommended that it was “better neglected”. But what Meyrick failed to realise was where, precisely, this tiny overlooked moth came from.

After a little sleuthing and a helping hand from modern technology, researchers at the Natural History Museum have come to a striking conclusion: this neglected specimen was collected by Alfred Russell Wallace around 170 years ago and is the type specimen for a diverse genus of moths.

Wallace is known for arriving on the theory of evolution through natural selection at the same time as Charles Darwin was formulating his own ideas. The two would eventually have their theories jointly presented at the Linnean Society of London in 1858.

Mark Sterling is a scientific associate at the Natural History Museum, and has been working with Dr David Lees, who is a Senior Curator of Lepidoptera, to piece together this amazing story.

“The specimen had been badly damaged and subsequently maltreated,” explains Mark. But that doesn’t mean that the specimen had no value. “This just shows with the advances in DNA sequencing that we are actually able to do something with a really broken specimen.”

As a result, not only were they able to narrow down the likely origin of the insect, but also use it to resurrect the genus Topiris, which now consists of 14 species, of which 11 are new to science. The results have been published in Zookeys.

A hidden Alfred Russell Wallace specimen

The butterfly and moth collection – known collectively as the lepidoptera – at the Natural History Museum contains roughly 13.5 million specimens. These cover more than 100,000 species, known and unknown, found on every continent apart from Antarctica.

Mark and David had been going through the collections trying to figure out a group of rather beautiful little snow-white moths from southeast Asia that sparkle in the light. They knew they had a number of new species on their hand, but a rather sad, crumpled moth specimen described in 1863 was holding them up.

The appearance of the insects suggested that the moths they were researching might belong to the same genus as the broken specimen but its substantially degraded nature meant they couldn’t progress much further. But there was also something else about this specimen that caught their attention.

Each specimen in the collections is labelled. Often, over time, individual scientists will add labels to the specimens recording something they think is significant or interesting. As a result, the labels themselves can sometimes become an important piece of information, almost like a library going back in time.

“You can tell a lot from a specimen label,” says Mark. “From things like the shape of the label or perhaps whether it has a black border or the handwriting, you get all sorts of clues as to where the specimen might have originated or who may have found it.”

While looking at the labels on the broken specimen the researchers noticed one that simply read “SAR”. This immediately piqued their interest.

Mark and David have become something of seasoned lepidoptera detectives. In 2023 the pair described a new species of moth discovered in Ealing, London, that was native to Australia. This required combing the Natural History Museum’s drawers and discovering a specimen of the same moth that has been sitting undescribed in the collections since 1886.

Once, in 2024 they were able to use their detective skills to piece together the extraordinary story of a new species of moth discovered in Port Talbot, Wales, that was actually native to Guyana, South America.

This time around, they were quick to realise that the SAR label is often associated with specimens collected by Wallace. This is because it stands for “Sarawak”, a region in what is now Malaysian Borneo that Wallace visited during his expedition through the islands of Southeast Asia.

They were further able to find references in Wallace’s own account of this expedition, published as the ‘Malay Archipelago’. In it, he recounts collecting moths from a bungalow near Kuching, Sarawak, between December 1855 and January 1856. This and other evidence led them to conclude that the moth was collected by Wallace at that time.

Old specimen, new techniques

At about the same time that this story was unfolding, the Natural History Museum was about to start a new trial in DNA sequencing. This latest technique only needed the smallest pieces of material to generate a genetic signature for a species from old museum specimens. David thought this moth would be an ideal candidate.

Taking a tiny piece of leg, the researchers ran it through the process and got back reems of data. After adapting an old computer programme and sorting through all the information, David and Mark were able to confirm that the broken moth was the same species as more modern specimens they had examined from nearby Brunei, and that a further 13 species that they had examined also belonged to the genus Topiris.

“This discovery highlights the incredible potential of modern DNA analysis to reveal the evolutionary history of species, even from fragmented and long-forgotten specimens,” explains David. “By applying this innovative sequencing technique, we have not only reconstructed the lineage of Topiris candidella but also expanded our understanding of this entire group of moths.”

From this insect they were finally able to complete their study, resurrecting the genus Topiris following the condemnation of the specimen by Edward Meyrick, and adding a further 13 species, 11 of which are newly described. Those newly described include ones named after Snow White and Cinderella, plus another named in honour of environmental activist Greta Thunberg.