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Oryctes : France : Lille : 59800 : 11/08/2024
Altitude : 37 m - Taille : 2,5 mm (estimation)
Réf. : 347235


Oryctes : France : Lille : 59800 : 11/08/2024
Altitude : NR - Taille : 2,5 mm (estimation)
Réf. : 347236

Hello,
I found this little fly today in my garden in Lille (North, France). It was on a bramble leaf.
I think it could be Scatella genus in the Ephydridae family. On LMDI the species S. tenuicosta is proposed. What is your opinion on this ?
Thanks in advance,
Dominique

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I would concur with the ID but please note that the correct name for the species now is Scatella lacustris.

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Thank you, Paul, for your reply. I take note of your remark concerning the change of the scientific name of the insect. The new name is therefore S. lacustris.
I was not aware of this change because I compared my fly to the species present in the LMDI gallery and it is the name S. tenuicosta which, for the moment, appears there.
On this subject, Eugène, from LMDI, tells me that "for the gbif S. tenuicosta still exists and is well mentioned in France"...
Sincerely,
Dominique

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I come back to the subject hoping to have some clarification from you, Paul, because as an amateur entomologist particularly interested in the Ephydridae family I have difficulty understanding the evolution of scientific names in relation to the species in question.
You say that the name S. tenuicosta is no longer current, that this name is replaced by S. lacustris but, as I have already pointed out, on LMDI where I come from, Eugene (who presides over the destinies of dipterology) says that, for GBIF and INPN, the species S. tenuicosta is still referenced.
In the LMDI gallery there are only the species S. tenuicosta and S. stagnalis (this species S. stagnalis, still according to Eugene and GBIF, would be a synonym of the species S. lacustris). Even in Diptera gallery I only found insects of the species S. tenuicosta.
All this leads to some confusion.
Which species name should we ultimately retain and use ?
Thanks in advance if you have time to answer me.
Sincerely,
Dominique

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Okay, tenuicosta remaining in the Gallery is my error. I will rectify that soon.
In the past, we recognised two species S. stagnalis and S. tenuicosta. These were considered to be the oldest names for these two species. Scatella lacustris was described after stagnalis but before tenuicosta. Before 2019 lacustris was thought to be the same species as stagnalis, but stagnalis is the older name and was thus be used for that species. Zatwarnicki & Irwin examined the type of lacustris and discovered that is was not the same species as stagnalis but identical to the species then still known as tenuicosta. Since lacustris is the older name, it should replace tenuicosta.
Name changes like these happen all the time and for those maintaining websites, databases, etc. it is not always easy to keep track of these changes and implement them (LMDI) or they lack the funds or experts to do so (INPN, GBIF). Please, note that most photos under the name Scatella lacustris in the GBIF gallery are correct and indeed thát species and that the referal to Scatella stagnalis is no longer correct. Most of these (if not all) were submitted after the 2019 publication and identfied using the newer literature. And I should know, because some of these depicted specimens were identfied by me...

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Thank you very much, Paul, for this very interesting and useful clarification (with all these details), and thank you for the time spent writing it.
It will certainly also interest the users of the World of Insects.
Dominique

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