Thread subject: Diptera.info :: Xanthogramma dives or stackelbergi female?

Posted by Ruth Ahlburg on 23-07-2014 20:27
#1
Copenhagen, Denmark, june 12, 2012.
Referring to this articke http://www.entomohelvetica.ch/pdf/ausgabe3/139_145_Spight_BUCH.pdf X. dives is acceptet as a separate species different from X. stackelbergi (and pedissequum).

The tip of the forewings ar darkened/infuscated, and the shape of the median, Black longitudinal stripe on frons indicate X. dives.

I called it X. stackelbergi because the staus of X. dives as a separate species was still uncertain in the Sweedish "nationalnycken" I used.

Thanks in adwance

Posted by ValerioW on 23-07-2014 20:40
#2
Right, dives female
Edited by ValerioW on 23-07-2014 20:52

Posted by ValerioW on 23-07-2014 20:51
#3
I would say, considering the country, dives/pedissequum . dives appears restricted to italy.

Posted by Ruth Ahlburg on 23-07-2014 21:23
#4
ValerioW wrote:
I would say, considering the country, dives/pedissequum . dives appears restricted to italy.


The abdominal membrane between each tergite and sternite is entirely yellow, except for between tergite and sternite 1 and tergite and sternite 2, where there is a broad,distinct, dark-grey band.
This make X. pedissequum impossible, as I understand it.

According to the Swiss article in the link neither X. stackelbergi nor pedissequum have darkened vingtips.

Posted by ValerioW on 23-07-2014 21:58
#5
'Impossible' is a great word, too big for this still debated issue. dives should have darkened wing tips, as your specimen has.

Posted by Fred Fly on 23-07-2014 22:23
#6
Its a female of X. dives which is quite commune in Central Europe.

Posted by ValerioW on 24-07-2014 08:21
#7
Piet Nord wrote:
Its a female of X. dives which is quite commune in Central Europe.



That it matches with (latest, not old, that didn't mention wing tip's darkening) dives ' descriptions is smooth and clear. Matter is that officially dives is only in the checklist of non-insular Italy, and for sure not in Germany or Netherlands or Denmark. Why there's a similar gap? I think that this "wing's apex darkened" Xanthogramma stackelbergi/pedissequum like is widespread, but there's no consensus yet about its detachment from the other two. Anyways, considering its particular traits (hind leg, wing's apex etc.), it appears to have dignity as independent species.
Edited by ValerioW on 24-07-2014 08:32

Posted by ValerioW on 24-07-2014 08:27
#8
Ruth, I just noticed that this photo was already in the diptera.info gallery. And I also see you put another dives/stackelbergi in the gallery, which actually cannot be fixed, considering an unchecked wing.

Posted by Ruth Ahlburg on 24-07-2014 13:59
#9
Yes, the male is discussed in this thread http://www.diptera.info/forum/viewthread.php?forum_id=7&thread_id=32554&pid=145396#post_145396.

A slight darkening on t´he wing-tip