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Hello,

I saw this Urophora sp. on 25 June 2020 in Switzerland. I posted this observation on another forum, where it was identified first U. jaceana, then U. cuspidata in a second time. It seems that it looks more like U. cuspidata than U. jaceana. What do you think ?

Seen on a Cyanus segetum.

Link to iNaturalist observation https://www.inatu...s/50869844
Link to the other forum https://www.insec...p;t=217991

Thank you!

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the only reliable difference is the fore femur with black stripe in cuspidata and entirely orange in jaceana

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Thanks a lot for your answer !

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Hello, the dark femur I exclud U. jaceana, ok.
But what is the criterion for excluding U. solsticialis ?

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Generally, males of U. cuspidata and U. solstitialis can be separated ONLY based on DNA barcode, or if reared from the flower head. Urophora solstitialis infests only Carduus spp., so the chance it is U. cuspidata is nearly 100%

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Thanks for the explanation !

So here to confirm the species it is necessary to exclude the presence of the host plant in the immediate vicinity.

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Yes, this is the way. However, some Urophora can visit the non-host plants: I collected U. terebrans, another species of the solstitialis group of species on Jurinea, but they never infested their flower heads