An Unexpected Visitor

Last summer I attended a Wildlife Trusts’ course on moth identification and trapping.  I found the course fascinating and was amazed to find out there are over 2,500 individual moth species in the UK alone!  They range from the impressive Death’s-head Hawkmoth, Acherontia atropos, with a typical wingspan of up to 13cm, making it the largest here in the UK. Through to the smallest, Enteucha acetosae, with a tiny wingspan of just 3mm, one of the worlds smallest moth species.  Some species of moth are just as beautiful as a butterfly, like this Elephant Hawkmoth, Deilephila elpenor, which is a bright pink and green, looking almost exotic.

Elephant Hawkmoth, Deilephila elpenor.

Returning home after the course, armed with my ‘Concise Guide to the moths of Great Britain and Ireland’, the knowledge of how to key species out, and equipped with a net and some specimen pots, I began hunting for moths.  Any unsuspecting moth that happened to find its way into the house ended up being caught and put into a pot for identification (do not worry, they were released unharmed once identified!).  This led to some amusing chases around the house and hours spent flicking through the book to see if I could correctly identify the species.

Common Swift, Korscheltellus lupulina.

On returning home one evening, a moth was crashing around the living room, shortly followed by me crashing around also, only for it to give me the slip and fly behind a cabinet.  A couple of nights later it reappeared and I managed to catch it.  I spent ages trawling through my moth book, but failed to find a moth even remotely like it.  I tried again and again but still with no results, so I turned to twitter, surely someone would recognise it?  Within half an hour I had had a few responses, “I know not what it is, but I like it!”, “Is this in the UK?!” and “I’m on the case, leave it with me!”.  By the following morning twitter had erupted in retweets, comments and messages, followed by emails and even a couple of phone calls!  This little moth seemed to be making quite a flutter.

Florida Fern, Callopistria floridness.

I was put in touch with Colin Pratt, who is the County Recorder for moths here in Sussex and validates records sent in from across the county.  Once Colin had the details and a couple of photos of the moth, the general consensus was that this moth was a Florida Fern moth, Callopistria floridensis. Usually found in Canada, Colombia, Puerto Rico, USA and tropical America. The reason why this chap was making such a stir?  It  had never been recorded in the UK before.

The story continued to unfold with another sighting, this time by a gentleman in Kent, who had a Florida Fern moth turn up in his moth trap in his garden.  Tony Rouse, similar to me, took to the internet and posted onto the Flight Arrivals page of Atropos, a website and journal for moth, butterfly and dragonfly enthusiasts.

Florida Fern Moth, Callopistria floridensis.

So the question was, where had they come from and what was one doing in my house?  Some research by Tony Rouse identified three records in Europe in 2016, these also appeared to be the first European records for the species, making both our finds the first records in the UK.  On learning more about the Florida Fern moth, the food plants for the species are ornamental ferns and foliage plants.  I am usually very careful when buying plants for the garden that I only source native species and grown here in the UK, most of the garden is purely for wildlife.  We had decided however, that the inside of the house needed brightening up and we purchased a Boston fern, Nephrolepis exaltata, which turns out is one of the food plants for the moth.  Inspection of our new fern did in fact show feeding signs, it is therefore thought that the Florida Fern moth caterpillar had pupated around the base of the plant and emerged indoors.

Boston Fern with feeding signs.

Although fascinating and exciting to have found something quite so unusual, it really highlights how easy it is for organisms to spread and how important biosecurity is.  Other moths have already colonised here due to importations related to ferns, for example Musotima nitidalis, which was first found in Dorset in 2009 and is now thought to be resident.

Great Britain has in place a strategy for plant biosecurity, developed and managed by DEFRA.  This looks at stopping the spread of pests and plant diseases before they reach our borders, as well as the management of them if they do become a problem here.  There are also separate management plans in place for tree health, which is especially important at the moment with three main issues having been identified, Ash dieback, sudden Oak death and the Oak Processionary Moth.

 It is still unclear as to whether Tony Rouse’s moth came from a garden centre, emerged from plants bought by a local resident or flew across the channel from Dutch or Belgian importers.  His specimen from Kent has been confirmed by DNA as a Florida Fern moth. My moth has been sent up to the Natural History Museum, as it is tradition for the first recorded specimens to be held in their collection.

Atropos 57th Edition

I recently received my copy of Atropos’ 57th edition which contains an article written by Tony and includes my account and photo’s of the moth before I sent it to the Natural History Museum.

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