Yet another moth with a very different common name in English compared to other languages. The common English name for Cataclysta lemnata is Small China-mark. I’m guessing that it has something to do with the colouration of this small, water-loving moth. In most other european languages the name of the moth refers to its favorite plant: duckweed (Lemna sp.). In Dutch for example, this moth is called Kroosvlindertje, in Swedish Andmatmott and in German Wasserlinsen-Zünsler.
Like last week’s moth, I spotted this one a couple of years ago during a lunch break in a nearby park. It took me a long time to determine it, mostly because I had not much extra information to work with. I found the moth sunbathing on a hardened footpath. No plant that might be helpful for determination. In hindsight not so strange considering that this moth was on a little vacation outside its normal habitat – a pond with duckweed. This moth lives a significant part of its life in and around water. The larvae and caterpillars feed on duckweed or related plant species and even create a cocoon in water. After the adults emerge, they remain on/near duckweed.
Feeding on duckweed is actually a pretty good choice as it is high in nutrients. In addition, they may be protected from certain predators, although living near water has its own predators and other challenges. To move between the duckweed, caterpillars use air bubbles, pretty clever for such insects! Small china-mark moths display sexual dimorphism, meaning that it is easy to tell the gender of the moth. The moth I found is a female; males are whiter in colour and a bit smaller. Check out this website for more pictures!