Forum europäischer Spinnentiere

Bestimmungsfragen (Determination) => Spinnen Europas bestimmen (Determining spiders of Europe) => Thema gestartet von: Raffaele Falato am 2020-11-12 19:58:19

Titel: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Raffaele Falato am 2020-11-12 19:58:19
Gorgoglione, Province of Matera, Basilicata, Southern Italy.

Discovery date: November 12, 11 a.m..
Habitat: 700 m - in an oak forest, in its safety net on a fence post, nearby there is an abandoned bungalow.
Dimensions: just over 3 mm.

Hi,
this spider, despite the red heart mark on the opisthosoma, reminds me of a male of Nigma walckenaeri.
Is my guess correct?
Thanks.
Raf

nw1.jpg
*nw1.jpg (25.57 KB . 703x523 - angeschaut 180 Mal)
nw2.jpg
*nw2.jpg (13.42 KB . 308x392 - angeschaut 190 Mal)
Titel: Re: Nigma walckenaeri male?
Beitrag von: Simeon Indzhov am 2020-11-12 20:11:21
It is *most likely*. I have had Nigma walckenaeri like this (with the red CM), rest of colour scheme fits and so does time of year. I would like other opinions though.
Simeon
Titel: Re: Nigma walckenaeri male?
Beitrag von: Raffaele Falato am 2020-11-12 22:18:23
Hi Simeon, thanks for your post.  ;)
After that, I did a little research and read somewhere that Simon speaks, for spiders like mine, of N. w. vulnerata, locating it in the Pyrenees region.
If so, it is clear that this variant, if it can be called that (I am a layman), is also present in other parts of Europe.
But perhaps the topic is already known to many of you.
Raf


Another observation, Simon describes the female, but his pattern is also common to the male.
Obviously if my male will be determined as such.
Titel: Re: Nigma walckenaeri male?
Beitrag von: Raffaele Falato am 2020-11-13 17:13:58
Oh oh, now I discover that vulnerata is a species, whose male is not known.
Titel: Re: Nigma walckenaeri male?
Beitrag von: Rainer Breitling am 2020-11-13 20:55:44
Hi Rafaele,
I think you were right in your first assessment: your specimen is very likely to be what Simon called vulnerata. Schmidt’s decision to raise this variant to species status doesn’t seem accompanied by any evidence. When we treat this “phantom species” in the future, I hope we will be able to use your figure 8)
Best wishes,
Rainer
Titel: Re: Nigma walckenaeri male?
Beitrag von: Simeon Indzhov am 2020-11-13 21:05:30
Thanks both for the research effort! I think I have a photo of my specimen too back from 2017 (which I guess would be a complement to knowing the form is present in many areas). That specimen is preserved (with colouration decayed) and I have normally coloured ones from the same populations.
Titel: Re: Nigma walckenaeri male?
Beitrag von: Raffaele Falato am 2020-11-13 22:31:55
Thanks to both of you.
I realize I have met a "particular" spider.
But this very interesting discussion has not reached its epilogue for me, now I have the problem of how to archive the spider:  >:(
1. N. walckeaneri var. vulnerata, which I believe is the most appropriate choice in Rainer's words (if well translated);
2. N. walckeaneri;
3. N. vulnerata.

@ Rainer you can use the photo when you need it ... but only if you explain to me why you consider vulnerata a phantom specie.  ;D  ;)

Greetings.
Raf
Titel: Re: Nigma walckenaeri male?
Beitrag von: Rainer Breitling am 2020-11-14 07:38:28
Hi Rafaele,
Nigma vulnerata is a suspected phantom species, because it is included in the check lists and databases as a valid species, but probably is just a variant of a widespread species, which would explain why (almost) nobody has ever seen it again, since Simon described it more than 100 years ago. There are surprisingly many cases like this, even in a well-studied area like Europe. In our two papers on “phantom species”, we already identified about 100 of them (and put them to rest). There are perhaps another 300 or more still waiting to be studied (it takes time and effort) – that would mean that almost 10% of European spider diversity consisted of phantoms when we started the analysis.
Best wishes,
Rainer
Titel: Re: Nigma walckenaeri male?
Beitrag von: Raffaele Falato am 2020-11-14 08:49:28
Thank you Rainer.
Greetings.
Raf
Titel: Re: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Raffaele Falato am 2020-11-25 18:36:41
@ Rainer. I think I have something that interests you and your future thread on ghost specie .

This morning I returned to the usual wood and, about 200m from the place of the male above, I found this female on a wild rose leaf ...

nwv1.jpg
*nwv1.jpg (14.35 KB . 356x343 - angeschaut 106 Mal)
nwv2.jpg
*nwv2.jpg (13.42 KB . 439x305 - angeschaut 106 Mal)

... and on a leaf just above this other female.

nw.jpg
*nw.jpg (36.79 KB . 482x597 - angeschaut 111 Mal)


In this small clearing, the classic form and the variant vulnerata live in the same buildings.  ;)

Greetings.
Raf
Titel: Re: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Rainer Breitling am 2020-11-26 09:41:47
Fantastic. This should definitely settle the case: these must be the same species.
Best wishes,
Rainer
Titel: Re: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Raffaele Falato am 2020-12-01 11:51:20
@Rainer
Update: the variant seems to be very common on the site I have under control, I continue to find both male and female specimens regularly.
It seems to prefer this type of plant (I don't know what it is):

nwh.jpg
*nwh.jpg (82.03 KB . 772x640 - angeschaut 54 Mal)

Six out of seven specimens had their webs on its leaves.

In your opinion, is it appropriate to report everything to the guys from Aracnofilia (association of arachnology + forum, the most active in Italy)? Maybe mentioning your impressions?
Thanks.
Raf
Titel: Re: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Rainer Breitling am 2020-12-01 12:14:57
Cool. Please feel free to share these findings more widely. Perhaps others will find similar mixed populations and can report on the ratio between forms in different places.
Best wishes,
Rainer
Titel: Re: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Jonathan Neumann am 2020-12-01 17:44:10
Does this form occur also here in germany? I never saw a Nigma walckenaeri with a red "heart".

lg,
jonathan
Titel: Re: Nigma walckenaeri male? => Nigma walckenaeri var. vulnerata
Beitrag von: Raffaele Falato am 2020-12-01 18:59:39
@ Rainer
Thanks for everything Prof, I am honored by your interest, your signorility and your availability.
All very important things for a layman like me.

@Jonathan
There's nothing left to do but go hunting.

Greetings from southern Italy.
Raf