Thread subject: Diptera.info :: Stevenia deceptoria ♀ to confirm--> Ok

Posted by rafael_carbonell on 17-12-2024 01:48
#1

The 7,8 mm ♀ fly was found indoors (Spain: Girona: Beuda, 16.vii.2021). In Spain only two species are recorded, S.deceptoria and S.umbratica.
This one looks quite similar to S.deceptoria:
- Vein R4+5 with setae only at base.
- Postpronotum with three setae arranged in a triangle (left humerus) or only two (right humerus)
- Parafacial with strong setae in lower half.
- Abdomen with no discal setae, but marginal setae: syntergite 1+2 with 2 median marginal setae, T3 with 2 median marginal setae, T4 with a row of marginal setae.
- Greyish dusting on syntergite 1&2 as well in T3 and T4
- Ratio of length pedicel/first flagellomere =11/15
- Orange ring at the end of antennal segment 2; palps also orange
- Tips of the femora reddish.
Was not observed:
- Abdominal tergites black with a clear posterior yellowish margin.(that was very narrow)

Edited by rafael_carbonell on 18-12-2024 08:14

Posted by rafael_carbonell on 17-12-2024 01:56
#2

And below drawing the position of setae

Posted by rafael_carbonell on 17-12-2024 01:57
#3

More photos and information: https://www.inaturalist.org/observations/255341793

Posted by Zeegers on 17-12-2024 12:07
#4

Yes, looks good, despite the absence of discals.

Theo

Posted by rafael_carbonell on 17-12-2024 12:41
#5

I see, there are also discals on Steven Falk's specimen (https://www.flic...9710183659). In my specimen they could have fell. Curiously, having or not discals is not important in the Stevenia key (Cerretti & Pape, 2007)

Edited by rafael_carbonell on 17-12-2024 19:40

Posted by Zeegers on 17-12-2024 22:19
#6

No, it is unstable in deceptoria, but when present, it directly excludes umbratica.

Theo