New species of tropical moth from Guyana discovered in Port Talbot living room

An unlikely sequence of events has led scientists to describe a new species of tropical moth found a very long way from home.

When moth experts Mark Sterling and Dr David Lees first saw pictures of the insect, which was discovered flying around a house in Port Talbot in Wales, they immediately knew it was something exciting. But little did they realise the detective journey it would take them on.

The insect was initially found by ecologist Daisy Cadet, who shares the house with her mum, Ashleigh. One winter’s day Daisy noticed a striking moth flitting around the living room. Moths aren’t Daisy’s area of expertise, but the insect’s remarkable appearance led her to catch and photograph it.

She posted the picture on Instagram and thought little more of it. That was until one of her followers noticed it and recommended that she get in touch with the insect charity Butterfly Conservation. They confirmed that it was an unusual find and put Daisy in touch with Mark and David at the Natural History Museum.

“It’s just wild,” says a shocked Daisy. “It’s not something that I expected would ever happen in a million years.”

“I’m so extremely excited about it, because my dream would be to go to the rainforest and discover a new species. I’m still just in disbelief at the whole thing and what’s happened.”

The full description of the moth has been published in the journal Nota Lepidopterologica. 

Tracking down the unidentified moth

Mark and David asked if Daisy could bring the two specimens she eventually found in her house to London. So, she headed east to meet the researchers and officially donate the moths into the Natural History Museum’s collections.

The researchers assumed that identifying Daisy’s specimens would be easy, but the process took rather more sleuthing than anticipated. The team needed to combine the moths’ appearance, DNA and a little bit of luck. 

They first ruled out any clearwing moths native to the UK. There are 16 species of clearwings that can be found here and the specimens looked superficially quite like one known as the yellow-legged clearwing.

But the timing of the discovery immediately ruled that out. Clearwing moths in the UK emerge during the summer, meaning there was no chance one would be flying around in Wales on a chilly February afternoon. So they started looking further afield.

“It looked externally like moths from the genus Paranthrenella, which is an Australian genus,” explains Mark. “But a lot of clearwing moths look quite similar, so that was at best a semi-educated guess.”

When it became obvious that the moth was not a UK species, the researchers asked Daisy to look through all the pot plants in her house to see if there were any pupae casings. Their theory was that insect larvae may have been brought into the country on one of these, or at the very least had been feeding on them, before hatching into its adult flying form. But after four days of searching almost 100 plants, Daisy returned empty handed.

Meanwhile, Jordan Beasley, who specialises in sequencing insect DNA, had been taking a much closer look at the moth. “It didn’t match any described species,” says David. “But it did show that the moth was closest to a group of seed-feeding clearwing moths that occur in Central America and the northern part of South America.”

The researchers immediately passed this information on to Daisy. “There was sort of a pause when we sent that email,” recalls Mark, “and then an email came straight back. Daisy said, ‘ah, if this thing could be related to clearwings from South America, then I have an idea.’”

Insights on its ecology

It turned out that Daisy’s mum Ashleigh, who’s a professional photographer, had just returned from a photographic assignment to Guyana. In the corner of the room in which the moths were found was Ashleigh’s boot bag. Daisy investigated and found two small, delicate pupal casings among the mud at the bottom of the bag. She also discovered a small piece of woody vegetation with what looked like bore holes made by the insects.

This not only gave the team a country of origin for this new species, but also the host plant on which the larvae had evidently fed. Collecting both the plant fragment and pupae, Daisy sent these to London for further analysis.  

“We then showed the plant fragment to Dr Sandy Knapp, who’s an expert on neotropical plants,” explains David. “Sandy looked at it and said that while it’s a bit difficult to tell from a small fragment, it’s probably part of a seed pod of a species of Mora, which is a big tree in the pea family that grows in the jungles of Central America and South America.”

Sending the plant fragment for DNA analysis, Jordan confirmed Sandy’s initial identification.

After the moth’s DNA narrowed the insect down to genus level, Mark and David were able to check the Natural History Museum’s extensive collections to confirm that it was indeed a new species. They named it Carmenta brachyclados in reference to a characteristically short hindwing vein and included Daisy as an author on the paper.

Despite never having been recorded in its native country, they were not only able to figure out where it came from, but also get a glimpse into its ecology and lifecycle.

Daisy and Ashleigh hope that the naming of the new species can help shine a light on the unfolding impact that the climate crisis is having on Guyana. This South American nation is under severe threat from rising sea levels and the destruction of the moth’s rainforest home.

“Whilst in Guyana, local people told my mother that if she left an offering of tobacco to the jungle spirits, she would be shown something beautiful from the jungle,” says Daisy. “So that is what she did.”

As the authors note at the end of the paper: It must have been very good tobacco.