New species of large moth found in Estonia

Scientific journal Zootaxa published an article last month describing a new species of moth discovered in Estonia and named Nola estonica. Photo: Villu Soon, Erki Õunap

One can only imagine the excitement of University of Tartu research fellow Erki Õunap when scientific journal Zootaxa published an article last month describing a new species of moth discovered in Estonia and named Nola estonica. A thorough study headed by Estonian scientists and aided by colleagues from South Korea and Russia took the better part of a year to finish.

In true gentlemanlike fashion, Õunap, who studies the taxonomy of moths, shared the honor of describing the new species with University of Tartu professor of entomology Toomas Tammaru. It was the professor who pointed to a specimen captured in Estonia and suggested it might constitute a new species years ago.

How often are new species of moth found?

Finding a new species of moth or butterfly is not that special in general. I believe that zoological journals describe new species every week. What is noteworthy, however, is that most of these species are discovered outside Europe, in tropical climate.

Finding a completely new species of moth in Europe, especially in northern Europe, is a much more significant event. For example, fewer than one species of moth a year has been described in northern Europe on average since the 1980s. Almost all are small moths/butterflies in whose case telling species apart can be very difficult.

How did you discover Nola estonica?

I share the honor of the discovery with Professor Toomas Tammaru. He suggested a decade ago that some very light specimens of Nola aerugula he had caught in Estonia were like others of the species and weren’t at the same time. There was reason to believe these specimens might represent a different species, but since there was no sensible answer in terms of which species that could be, the matter was left at that.

When I sequenced one such specimen’s DNA in May of 2020, it was immediately clear that something was off. A few weeks later, we knew we had discovered something that was new to Estonia and Europe. This is where the peculiarities of biosystematics came into play – not every organism that you fail to recognize automatically constitutes a new species. You need to study all available literature on that particular group of species, and only when you have ruled out all existing species can you set about describing a new one.

That is precisely what we did. It became clear in the summer of 2020 that a species of the family Nolidae found in the Far East is quite similar to the species we had found in Estonia. Working with colleagues in South Korea and Russia, co-authors of the study, we concluded in February that the Estonian moths are not members of that eastern species and the species found in Estonia is indeed unknown and in need of a scientific name.

Writing the article took a fair bit of time, plus the editing cycle at the Zootaxa journal, which is how the publication of the species description became a kind of Christmas present for the authors.

What makes this find extraordinary?

The place where it was found. The world has no other region where the fauna of large moths, that include the Nolidae family despite their diminutive size, has been studied as thoroughly as in northern Europe. A completely new species of large moth was found nearly 40 years ago, and even though all northern European countries have always had good entomologists, Nola estonica had not been described before.

What does a lepidopterist feel in moments like that? Winning the lottery is not far off as a comparison I presume?

Considering the circumstances, it is difficult to compare the moment to anything at all. The first feeling I had was disbelief as we had considered it impossible to find a new species of large moth in northern Europe. Because new data soon proved the matter to be more than wishful thinking, I felt obligated to turn the discovery into a scientific description of a new species as best I could.

True satisfaction – which I believe is felt by everyone who successfully concludes a long project – arrived only when I received the letter telling me the article had been published on December 21. We have received sincere congratulation from colleagues in Estonia and elsewhere to demonstrate we truly did something special.

As concerns comparisons to winning the lottery, certain elements to that effect can be found in the story of Nola estonica’s discovery. Public databases suggest that the DNA of Nolidae specimens has been sequenced in Europe in the past, including that of light specimens. However, it has somehow happened that specimens of the species we described were never included in those studies. Even though it might have turned out differently.

The reason the discovery cannot be fully compared to winning the lottery is that luck alone was not enough. Things would not have gone this way without the authors’ decades worth of experience as moth collectors and lepidopterists.

How is a species named?

Scientists have quite a lot of freedom when describing new species. The name needs to have at least two characters and be pronounceable. For example, you cannot call a new species “e” or “xx,” while you are otherwise rather free in your decisions.

In this case, the connection should be rather self-evident. We went with the name estonica because we discovered that it was a new species thanks to specimens caught in Estonia.

How many species of butterfly/moth have been described in Estonia?

Only a few species have been described based on specimens found in Estonia. I can recall two species of Geometridae and one species of Noctuidae in the case of which Estonian scientists have used local material to show that something else exists on top of established species.

Are some regions more diverse than others in terms of number of species and therefore sport greater potential for discovering new species?

Southern Estonia and Saaremaa are the most diverse. Natural conditions provide a more diverse fauna in those areas, while new species migrating north as the climate warms also first arrive in southern Estonia or Saaremaa.

Finding entirely new species in the northern part of Europe is challenging, while the discovery of Nola estonica proves it is still possible even in the 21st century.

Mass DNA sequencing is the most promising method of discovering a new species and there are several examples where several different species have been discovered from among specimens that all look the same to the human eye.

What is the preferred climate of moths/butterflies?

Looking at number of species alone, it is equatorial, especially tropical rainforests. That said, tundra and mountain ecosystems also have their species. Only Antarctica is completely uninhabited by moths/butterflies.