Is this a Northern Deep-brown Dart, Aporophyla lueneburgensis or just a Deep-brown Dart, A. lutulenta? Nobody seems to be able to decide definitively, there’s a taxonomic debate raging among lepidopterists. Some record keepers will allow “aggregate”, others accept only the latter for the UK…it’s all very confusing. I’ve only been mothing since 2018, after all.
Moreover, some experts cannot decide whether they are two species or one, where either or both lives, and even whether the Northern one is actually predominant in the South. That said, there do seem to be two distinct larvae, so two species, the question then is whether or not we have both in the UK.
Now, to my inexpert eye the two specimens I have photos of here look rather different. But looks aren’t everything when it comes to moths. Some moths can vary a lot from specimen to specimen, such as the Lunar Underwing, which can be dark or light and vary in terms of the patterning on its wings. Other moths of entirely different species can look very, very alike, Dark Dagger and Grey Dagger, for instance. In fact, these latter two species cannot be distinguished based on their superficial appearance but only by dissection and examination of their genitalia, so-called “gen-det”.
So, if the moth above is either a Northern Deep-brown Dart or a Deep-brown Dart, is the specimen below a Deep-brown Dart or a Northern Deep-brown Dart. Both, either, or just one have been in my garden. There’s a French paper that talks about the genomes of two specimens that were purportedly one of each as being the same and our local list has settled on DBD. But, there’s also work in Poland that shows the genomes to be sufficiently different to think of them as two separate species. Nothing is ever settled in taxonomy, as many of you will know, it is and always has been a dynamic science, DNA science just added to the evidence and clarified some of the confusion in some areas but raised doubts in others. There is always debate and change.
I don’t know enough about these/this species and seemingly neither do the lepidopterists to decide one way or the other…yet. I have recorded them in my personal logs as two species, Northern DBD and DBD, but when they settle on the science, I will update those records if I need to. I’ll leave my County Moth Recorder to decide either way when I submit them at the end of the year.