Flat-backed Millipede - Polydesmus angustus?

[JRsbugs]

Hi,
Found on 5th December 2008 on my kitchen floor. It was about one inch long and could 'run' quite quickly but not as fast as a centipede. This autumn seems to be a Millipede one, I have so far come across three different ones inside!

Can anyone say if this is correct? Thanks!

Janet

[Paul mabbott]

Yes, one of the polydesmid millipedes (Polydesmida is one of the six [I think ] orders of miilipedes, Diplopoda, in UK]. The other, largest, order is the Julida which are more tubular and shiny. Yes. you'll find a lot of millipedes at this time of year.

Originally Posted by JRsbugs

Hi,
Found on 5th December 2008 on my kitchen floor. It was about one inch long and could 'run' quite quickly but not as fast as a centipede. This autumn seems to be a Millipede one, I have so far come across three different ones inside!

Can anyone say if this is correct? Thanks!

Janet

[JRsbugs]

Thanks Paul! Thank you also for the extra information, I have two in Julidae, now I want the rest, lol.

Janet

[JRsbugs]

I found a pic of an engraving of Polydesmus complanatus on nature.british-towns. There's also two pics of Polydesmus angustus, which doesn't look at all like mine but a google search shows many with that name which look like mine. I would have thought that site had them correct?

I see some sites referring to Polydesmus inconstans, which is listed on british-towns site with that name, as Polydesmus coriaceus, but on micropics.org they have given it the alternative name of P. gallicus.

Whatever the alternate name, the one that micropics they call Polydesmus coriaceus looks to fit mine well, the shape of the segments, tail end has a rounded shape under the tip, number of segments tallies. Overall it looks to be the same animal, I have noticed on that site if there is doubt they put a '?' after the name.

As it appears the updated name is Polydesmus inconstans, does anyone have anything, such as literature or photos in a book which would confirm that? There is so little on the net about these, and some it would appear have been given incorrect names.

Polydesmus superus is a possibility too, there are pics of it on bioimages but appears to have been called Brachydesmus superus. The pics however are a bit washy, but it does appear to have those little round lumps at the edges of the tergites.

There are also pics of Polydesmus angustus on bioimages, that one does look like mine, and I can see the gonopids too! So the pics on british-towns are not correct it would seem, but is probably a pale specimen?

I think it has to be Polydesmus angustus.

[Pudding4brains]

I just lost a lengthy answer I compiled due to a computer glitch

So ... sorry for the shorthand:

Please be careful with named beasts on the internet - especially with less wellknown groups these are more often wrong than right.

Your animal might well be P.a., but I'm certain you looked (mostly) at the wrong characters. Experts have a hard time distinguishing the larger Polydesmidae from photo and often use distribution data as a second option.

Have a look on my old scratchpad (in dire need of update) for some links. Follow the two links "Bestimmung" near the top for fairly comprehensive keys and get the volumes of Faune de France by Brölemann linked near the middle of the page.

Gotta go - cheers! Arp

[Paul mabbott]

I can only reinforce what Arp says - some of these are difficult to tell apart when you have them under a good microscope; naming them to species from a photograph is unlikely to be reliable - espcially since, for many invertebrates, you need to examine their underside features, particularly the genitalia. Unless you can get a real expert to confirm a species name then be content to get it down to (e.g.) Polydesmus sp..

Some of the identifications on the web are arrant nonsense! People are keen to put a name to things but it should only be done when you're certain .... and that means expert advice!

Originally Posted by Pudding4brains

.............
Please be careful with named beasts on the internet - especially with less wellknown groups these are more often wrong than right.

Your animal might well be P.a., but I'm certain you looked (mostly) at the wrong characters. Experts have a hard time distinguishing the larger Polydesmidae from photo and often use distribution data as a second option.

Have a look on my old scratchpad (in dire need of update) for some links. Follow the two links "Bestimmung" near the top for fairly comprehensive keys and get the volumes of Faune de France by Brölemann linked near the middle of the page.

Gotta go - cheers! Arp

[JRsbugs]

Thank you Arp! I can recognise the lengths on the sites, but would have to do a babelfish translation for the rest! But I can do that if needs be.

I just managed to download the PDF too, might have trouble with that too, lol!

As you mention, location can be important, I think there are only 6 species of this Genus here and I found Polydesmus angustus is the most likely to be seen. I also read it is fond of strawberries, which I grow too!

Thanks Paul, yes I agree, and I am learning fast!

Janet