We were lucky that we could travel to Finland again. We visited Liesjärvi from July 15th to August 12th. We just arrived at the end of a heat spell. Never ever I experienced that the lake water was 31 degrees Celsius. 2021 also was a very exceptional butterfly and dragonfly year, at least during our stay in the summer cottage.
- Never before did we observe such large numbers of Keiserinviita (Argynnis paphia; 165 observations) and Suruvaippa (Nymphalis antiopa; 105 obervations). Suruvaippa occurred already halfway July, whereas in previous years the first individuals of the autumn generation could be observed around end July – first week of August.
- Also, Nokkosperhone (Nymphalis urticae) and Sitruunaperhonen (Gonepteryx rhamni) occurred in relatively high numbers.
- In contrast, Orvokkihopeatäplä (Argynnis aglaja), Ketohopeatäplä (Argynnis adippe) and Angervohopeatäplä (Brenthis ino) were very rare. Even more strange was the complete absence of Niityhopeatäplä (Boloria selene), which is usually a common species. Also, there were not many Sinisiivet (Polyommatinae).
- For dragonflies, the summer of 2021 seemed to be dramatic. It was very hard to find any exuviae. I searched several lakes, but hardly found any exuviae (n=42), whereas in previous years I easily found >300 exuviae per year.
- Maybe the dry and hot summer caused these unexpected observations in 2021.