Hot summer brings new butterfly species to Estonia

This year's unusually long, hot and dry summer in Estonia has led to at least one species of butterfly appearing which hadn't previously been found in the country.
Examples of the Wall Brown butterfly (Lasiommata megera), in Estonian 'kirju-tumesilmik', have been found in both Pärnu County and the island of Ruhnu, which is the first recorded sighting of the species in Estonia, current affairs show 'Aktuaalne Kaamera' reports.
The butterfly's usual range extends through much of continental Europe, North Africa, the Middle East and parts of Siberia and the Central Asian Republics. It had previously been seen in Latvia, but this summer brought the first Estonian sightings, according to a University of Tartu Natural History Museum spokesperson.
"Such an unusually warm summer is undoubtedly a factor in bringing the species here from more southerly climes," said Andro Truuverk, an entomologist (studier of insects) and discoverer of new species of butterflies.
Will more species of butterfly be found in future?
Whether the trend of more new butterfly species will continue into the future remains to be seen, according to Mr. Truuverk.
''This will certainly be the case with moths, but butterflies are a bit more of a complex question,'' he said, adding that whilst new species of moths get added to the list of Estonian fauna every year, the last butterfly to be added happened over 20 years ago.
''There are around 2,000 known species of butterfly in Estonia, of which about half are larger species, the rest are micro-species'' Mr. Truuverk continued.
"If we consider that butterflies fall under the Macrolepidoptera group and this wall brown was Estonia's 114th species of butterfly to be added, this demonstrates a probability of one in nine of finding a new species going forward," he said.
''But there are so many more species of moths that the likelihood of more new species of those being found are far higher,'' he went on.
Truuverk also added that this is not just some outlying incident and that the Wall Brown species haven't just found their way here by accident, but that it is likely they have intentionally expanded their range into the Estonian wilderness and have set up home there, so to speak.
''We have no lack of food or habitat here so the species is likely to remain here for as long as conditions remain favourable to it,'' Andro Truuverk went on.
''What was most telling was that very shortly after the example was found in Pärnu County, another Wall Butterfly was found on Ruhnu,'' he added.
The orginal story and Aktuaalne Kaamera clip (in Estonian) is here.
Editor: Andrew Whyte