We run a moth trap at Blashford on most nights of the year, we record the species and numbers. Some species are regular and others we see only once every few years and just occasionally we get a new species. When I opened up the trap yesterday morning there was a moth I had never seen before, small but quite distinctive.
When I looked in the book I could not find it, luckily the internet came to my rescue and I managed to identify it as a Pyralid moth, Musotima nitidalis a species native to Australia and New Zealand and first found in the UK in 2009 near Bournemouth.
So how did it get here? It appears it feeds on tree ferns and is likely to have been introduced with plants imported from Australia. It seems it will feed on some native fern species here, such as black spleenwort and bracken. Now it is here it will probably stay, perhaps as a scarce insect having little impact, or perhaps not. Once alien species establish the consequences will only become clear many years later and certainly there is nothing we can now do about this particular one but wait and see what happens.