Lovely individual, posed nicely for you.
These two species cannot be separated by wing patterns - because, as you have found out, they are similar and variable. From photos, it may be too late to make a reliable ID.
- If the moth is female, you can distinguish these species only by examination of the genitalia.
- If the moth is male, you'll have to look closely at the antennae: look from the side, not from above:
- T. britannica: the segments progress from being narrow at the root, through square in the middle, to elongated at the tip
- T. variata: the segments are nearly square
- For both female and male, see the text here ('Diagnose' section):
I hesitate to say this...
Have you also considered T. cembrae?
With all three species, I do not know about their distribution in Italy; I leave that to you.
sorry for the delay, I'm back right now.
So, I think you're right, there is the T. cembrae too, and it's eem a good choice too.
I tried to zoom at the antennal segment and they are squared, but I don't know if it's a male or female
I think I leave only the genus.
thanks for your help.
Using only the genus is, of course, safe.
You could, however, try to make use of the 'aggregate' name qualifier.
Some species (plants, not just animals) are very similar, and for practical purposes (especially in the field) they can be referred-to by a name that covers all the confusable species. For instance, some blackberry relatives can be called Rubus fruticosus agg.
In our case, there is not a recognized aggregate name for our confused species of Thera moth, but we could adopt:
- Thera britannica agg., or
- Thera britannica-variata-cembrae agg.
The former may be more acceptable, according to usual naming rules,
but the latter is more explicit since it details the species involved (but I have invented the epithet 'britannica-variata-cembrae' without formal publication as an aggregate name).
I would actually appreciate comments from professional taxonomists on this matter!
(if any happen to be lookin-in)
More photos of Thera britannica antennae here - http://www.mothscount.org/uploads/Difficult_species_guide_page_28.pdf
Yes, it could be an idea, sometimes it happen with the Diptera too, if there exist a "group" we write "Drosophila repleta group", the group "repleta" include many similar species", or we write "Drosophila melanogaster/similis", when there are 2 similar species that could be distinguesh only by the genitalia analysis.
So, I don't know if the Thera sp. have a group that include similar species, but I like the agg. Thera britannica-variata-cembrae.
Thanks for this suggest
PS: I'll ask to a Diptera taxonomist if it could be used.