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I photographed this 5–6 mm long fly yesterday in a garden in southwestern Germany. Can you say more than Tephritis?

Greetings Siggi

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pic. 2

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Jordi Clavell and Valery Korneyev have identified the insect on Observation.org ( https://observation.org/observation/406612294/ ) as Tephritis formosa.

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I have spent some time studying the genus Tephritis and am of the opinion that one cannot reliably identify the specimen as Tephritis formosa based on these images. Therefore, I prefer to leave it as Tephritis sp.

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1 Both Merz (1984) and Smit (2010) consider Tephritis formosa "unverwechselbar".
2 Google Valery Korneyev.

Ben

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Generally, i see no problem at all; there is no other species like this you could misidentify in Europe. There are some doubts about Caucasian or Moroccan populations, which show certain genetis distrance, but all the German specimens on Sonchus oleraceus are like this, with widely black pattern generally with numerous isolated hyaline dots (their size slightly vary, indeed) and two apical dark spots.
We have revised the whole group of species (Korneyev & Korneyev 2019, Zootaxa) and if you like I can share it with you via ResearchGate.

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Hello everyone,

Thank you very much for your comments. I’ll try to explain my point of view and would like to emphasize that I’m a layperson and don’t claim to be scientific. Nevertheless, it’s important to me to post my photos with a reliable name. If I can’t confidently identify the species, I’d rather stick to the genus or even just the family.

Tephritis formosa was also my first thought. However, upon closer inspection of the photos, I noticed that this insect looks different. The central black spot on the outer edge of the wings lacks the V-shaped notch typical of that species. Since I’d read online that the wing markings are species-specific (i.e., not variable), I ruled out Tephritis formosa and posted the photos on Diptera-Info. The fact that I didn’t receive a response on this forum at first confirmed my doubts. From this, I concluded that identification probably isn’t that simple after all.

When Jordi Clavell then classified the photos on Observation.Org as Tephritis formosa, I initially accepted the result and continued to study this species. There are apparently two main characteristics that supposedly make the species unmistakable.

1) Two dots on each otherwise unmarked wing tip
2) The relatively straight and transverse edge of the black patch.

Val, you write that the specimens found in Germany cannot be confused with any other species. But what about Tephritis bardane, for example? This species looks very similar (at least to my untrained eye) and is also found in Germany.

I also photographed this fly in our garden on June 21, 2026 (see new attachment) and identified it as Tephritis formosa. In my opinion, this is what that species is supposed to look like. But there’s clearly a difference between it and the insect in question here.

Incidentally, the insect in question was sitting on Urtica sp. Both Sonchus oleraceus and Arctium sp. are found here.

I don’t mean to offend anyone here, and I’m happy to be corrected. But of course, I also want to understand why an insect can be identified—or why it can’t.

Greetings Siggi