Thread subject: Diptera.info :: Bithia acanthophora? (Tachinidae) --> Bithia modesta

Posted by rafael_carbonell on 20-09-2012 22:45
#1

I've tried to identify this tachinidae with the palearctic interactive keys, as some legs and bristles are absent, and got Bithia. Following Bithia, in the dichotomic centraleuropean keys I got B. acanthophora. In the same keys, as I could'nt see all characters needed, or did'nt them clear, it could also be Fausta and Eurithia (more rarely Meigenia or Blondelia). I don't know which sex could it be.

In the picture its showed, between others, mid tibia II (the unique left) (in a strange position)and humeral callus.

1st july 2007, Spain: Catalonia: Girona: Beuda, 395 m.

Leghth: about 9 mm.

Head: Bare eyes. Frons width in the narrowest point dorsally: 2.15 mm; Eye width (the same): 1.65. Parafacial (cheeks) entirely bare below lowest frontal seta (but short pubescent). Lower facial margin slightly visible in lateral view. Postero ventral part of
head with a majority of white hairs. Laterally gena 0,85 in lenght and eye (vertical) lenght: 3.7 (rate: 0.22).

Mouthparts: Vibrissa at height of mouth edge. Above the vibrissa only a few hairs or bristlets on the lower 1/5 of the facial ridges. Dark brown palpi. Haustellum (=prementum) of the proboscis slim (lenght/wide rate at 4.5) and shorter than the maximum eye diameter.

Antenna: antenna longer than height of gena. Arista with short pubescence (hairs at most reaching length of basal diameter of arista)(and that takes out Zeuxia)., thick in the basal 1/3, and the 2nd segment no longer than its diameter. 3rd antennal segment without a pointed tip at the distal end.

Thorax: 3 interalar bristles behind the thoracic suture. Sternopleural (=Katepisternum) with 3 setae. Postpronotum (humeral callus) with 3 setae in a straight line, BUT (and that takes out Bithia) one a bit more advanced than the other 3. The strong subapical scutellar bristles apparently stronger than the apicals (both four are accidentally missing). Pre-alar bristle shorter and weaker than the notopleural. Prosternum (apparently) bare, but very short pubescent. Scutellum without lateral bristles (just hairs or small bristlets), but one strong basal bristle.

Wing: R5 closed just at wing edge. Bend of M with an obtuse angle before margin (and that takes out Zeuxia). Vein m-cu not noticeably slanted. The section of m between r-m and m-cu is longer as that between m-cu and the deflection. r4+5 with 4-5 bristlets extending to 1/8 to rm. r1 and cu1 bare. Calyptrae bare on their surface, with fine hairlets only at the edge; lower calyptra spoon shaped. Tegula black. Basicosta medium brown.

Abdomen: Synterguites I+II depression at 7/8 of its lenght; terguites 3 and 4 with 2 median discal setae;


Is Bithia acanthophora oK? I have more detailed pictures if needed. Thanks in advance

Edited by rafael_carbonell on 25-01-2023 23:44

Posted by ChrisR on 21-09-2012 09:52
#2

It does look like Bithia but the specimen has suffered quite badly - how are you trapping them? I am not very familiar with the species in Spain so I won't comment without a specimen to look at ... but Theo might be able to help Smile The Central European key might work but I think it would be too unreliable in the south.

Edited by ChrisR on 21-09-2012 09:53

Posted by rafael_carbonell on 21-09-2012 10:43
#3

Chris, I usually don't trap flies (except Musca, Phlebotomus and Culicidae) I just clean the house Smileand collect all the died insects (as throwing them to the chicken would be a biodiversity loss).

Thanks anyway, we will wait if Theo or someone else looks at it.

Rafael

Posted by Zeegers on 25-09-2012 20:44
#4

It could be Bithia, could be not.

I see two options

-1) use the new interactive key on www.tachinidae.eu.
Very useful in case of missing features !

-2) send it over to me
In case of a rare Bithia, like acantophora, I'd like to see the specimen myself.

Despite the excellent job you did in describing it !

Theo

Posted by rafael_carbonell on 25-09-2012 21:50
#5

Thanks Theo

In fact the text is just the one is taken out using that keys!!

The problem is that I don't know If an animal with just one leg left is enough for serious identification.

I'll be glad of sending you this animal (you could keep it), you can give me your physical address in a private message.

But I would like to wait a bit more, there are some other tachinids I want to try to identify first.

Best wishes,

Rafael

Posted by Zeegers on 27-09-2012 20:17
#6

An animal with one leg is not optimal, but in many cases I can get an ID, surely to genus level.
Of course, it is more difficult, moreover, the Iberian peninsula is not my home area, so that is why I'd need the specimen.

I will send you a PM with my address.

Thanks


Theo

Posted by rafael_carbonell on 25-01-2023 23:07
#7

Finally determined by Theo Zeegers as Bithia modesta.

Edited by rafael_carbonell on 25-01-2023 23:45