Latest Collembola Research (and specimen jar images)

[Jason Green]

Hi all,

I have recently been in touch with Frans Janssens, having had a few things I wanted to ask of an expert in Collembola. A nice man, and very quick to reply to emails.

I asked about the Dicyrtomina saundersi, and maybe ornata being a colour pattern according to some sources. Apparently the Globular Springtail Dicyrtomina ornata and saundersi are likely two seperate species though DNA research hasn't settled the debate yet. Frans says that as they are both physically different in certain areas it is likely they are seperate.

If you look at the back of a Dicrytomina ornata or saundersi, you'll see the vertical line and variable horizontal-lines that are used to identify the individual (strong left-right lines say saundersi, see my photograph below). This structure is possibly there to prevent predation by imitating an Orthopteran, or generic hexapod. See Checklist of the Collembola: Note on a case of predators'-predator-mimicry in Dicyrtomina

There is a third Dicyrtomina sp. as well, known as D. minuta. See here for images: Dicyrtomina minuta - Google Search - as I haven't seen this one before. One to look out for I think!

I also took the opportunity to enquire about any latest research regarding Entomobrya intermedia and nivalis.

He told me:

E. intermedia and E. nivalis are 2 different species. They are often confused though.

I asked him about the Hopkin site and the inclusion of intermedia and nivalis as the one. He told me:

Hopkin considered intermedia specimens as nivalis. He based his decission on the few (and distorted) slide mounted specimens that were/are available in the MHNL collection. But the difference is obvious if you observe alive specimens.

...indeed. He stated the differences to look for as being:

To distinguish them look at the U-shaped pigmentation pattern on the long 4th abdominal segment:in nivalis the corners of the U-shape are 'closed', 'touching'in intermedia those corners are 'open', not 'touching'.

To compare patterns, check: Checklist of the Collembola of the World

upper = nivalis; lower = intermedia

My Images:
I took my specimen jar outside to get ventral images (in the hope of finding an invertebrate that can be better ID'd from the ventral or underside perspective), where I found a Dicyrtomina sp. The resulting image shows the jumping gear below.

...unfortunately a little dark. 3-4mm

Next up, a Tomocerus vulgaris I believe. It was a good 5mm+ specimen including antennae. It gave a good view of the furcula, as you'll see.

My next ventral-subject will be an Entomobrya intermedia and hopefully nivalis (I've only had the opportunity to photograph one individual - but somehow lost the photo ), as well as any others.

He has also asked me to let you know about his Flickr project - it sounds like a good way to get involved. I'll let him explain :

Feel free also to invite people to join our Collembola project at Flickr.com Uploaded Collembola pictures when properly tagged (tag 'Collembola' is the minimum) will be IDed. And when geotagged they will popup at our global Collembola distribution map

.

An interesting subject I think. Thank you for reading!

Take care,

Jason

[Bruce Williams]

A very interesting post Jason - thanks.

Bruce

[Lord V]

Good stuff Jason - I've never spotted D. minuta but get D. saundersii and D. ornata all over the place in the garden.
Brian v.

[JRsbugs]

With all due respect to the man you emailed, Frans Janssens is from the Royal Entomological Society in Antwerp so his qualifications would indicate him to be suitably qualified. It wouldn't be the first time experts disagreed.

Intute - Animals

Here we drag up the same old argument over E. nivalis and E. intermedia. I have seen that Steve Hopkin's images of what he has called E. nivalis have been placed with E. intermedia on Frans Janssens Collembola site, as Mr Hopkins is no longer around to query this I wonder what he would have thought about it if he was. Maybe the images were placed there before his passing and with his permission? At least the name has not been changed.

The very fact that Steve Hopkins had not even given a full write up for E. intermedia on his site as he did some other species which were in doubt leaves me wondering if there was as yet insufficient evidence to say anything about it.

If you would take the time to read about Steve Hopkins qualifications you might see that he was a world leading expert in Collembola, he wrote the key to the British species as well as many papers on world Collembola. If you look at the descriptions of many of those in the UK on his site, you surely can see that far from going on old dusty specimens he had been extremely cautious in either lumping species together or separating them. To the contrary, in many cases he had examined museum specimens and found them to be different species to what they were labelled. He used factual information and often DNA technology, which any professional entomologist would do.

Collembola of Britain and Ireland

Read about Steve Hopkins here...

Steve Hopkin

If you are interested in finding out more about Collembola, I would suggest contacting the person who has taken over from Steve Hopkins. There is a page on the Roehampton site about E. intermedia, it appears records are being accepted due to 'popular demand' as there has been a flood of photos on Flickr which have been identified by Frans Janssens. You should take note of the comments, in particular:

This species appears to be widespread and common, but has been widely confused with E. nivalis to the point that the distributions of both must be suspect. Gisin (1960) considered this species a junior synonym of E. muscorum, while Steve Hopkin dismissed E. intermedia as probably a junior synonym of nivalis, and specimens of this species will key down to nivalis in Hopkin (2007), ensuring that the names will remain confounded by UK researchers for decades to come!

(185ENint) Entomobrya intermedia (Brook, 1884)

I also find this interesting..

Although outside the distribution range shown on this Dmap coordinate set, a recent set of photographs from Jersey (2 sites about 6km apart) show an Entomobrya whose abd 4-6 correspond well to E. intermedia, except for a mid-line stripe on the thorax that, coupled with 2 lateral stripes, makes it intermediate between E. intermedia and E. handschini. The images are copyrighted but have a hyperlink here. Until specimens can be collected and examined it is not clear whether this is merely a colour variant or in fact a new species (an island endemic – Frans Janssens suggested E. intermedia "jerseyensis", but this name has no taxonomic validity at present.)

If the future of records is swayed by popular demand this surely doesn't account for accurate records. As Steve Hopkins had found specimens of E. intermedia keyed out to E. nivalis, and as yet his accounts look to be the most accurate (I have found no other scientific accounts on these!), I won't be swayed. Also, remember there are variations in pattern on other species so I don't see why this one should be an exception. I have found it's a common thing for people to be swayed by popular thinking rather than scientific fact, if anyone has updated scientific information I would be interested to know.


The full list with accounts of species in the UK is on the Roehampton site..

Taxonomy

I think I have E. minuta.

Janet

[JRsbugs]

I think I have E. minuta.

Make that D. minuta! I'm not absolutely sure although there is some blue pigment visible.

[Jason Green]

Thanks Janet

Originally Posted by JRsbugs

If you are interested in finding out more about Collembola, I would suggest contacting the person who has taken over from Steve Hopkins. There is a page on the Roehampton site about E. intermedia, it appears records are being accepted due to 'popular demand' as there has been a flood of photos on Flickr which have been identified by Frans Janssens. You should take note of the comments, in particular:

(185ENint) Entomobrya intermedia (Brook, 1884)

On the Roehampton site's intermedia page; Between those two (second and third paragraphs on this page (185ENint) Entomobrya intermedia (Brook, 1884)), you'll find two possibly relevant paragraphs in my opinion...

There are a couple of literature records for this species (...Edit: Referring to intermedia), but since 2007 there has been something of a surge of records of this species as enthusiasts have uploaded images to the Flickr image-sharing website, followed by confirmation of ID by Frans Janssens who has added many helpful comments about field ID to many springtail photos, such as here - http://www.flickr.com/photos/77849983@N00/2104723167/. I have accepted Entomobrya intermedia records from this site as long as the photos show abdominal patterning adequately. Happily this species frequents open surfaces and has its abdominal patterning as its most conspicuous feature, hence the surge in new records.

A check of all Entomobrya photos on the Flickr site in February 2009 found at least 10 good new records (clear photo plus location plus date), and it is very likely that more remain to be found. This appears to be the second case, at least for springtails, where web photographs have not just confirmed a species but transformed its distribution map! (The first case was a story related by Arne Fjellberg, who identified the first record of Orchesella flavescens in Norway from a web-image, then followed up by visiting the site and collecting specimens to confirm the ID*). Re-assuringly, good numbers of E. nivalis, E. nicoleti and E. multifasciata also featured, sometimes co-occurring but all showing clearly different colour patterns.

I have no intention of debating it either, I'll leave that to the experts out there! I believe intermedia does exist as a different species, and if you don't that's fine.

One last thing:

Originally Posted by JRsbugs

I also find this interesting..

...in my opinion, it's a possible new species or even sub-species concerning one individual - not an attempt to rescind intermedia as an entire species

*Glad to see a voucher collection's importance being mentioned in addition to photographs!

As for D. minuta, please post it! I thought I'd found one in the past, but the photo shows it surrounded by saundersi so I suspect I haven't as yet - it must have been a, pale, juvenile. Hopefully you have!

[JRsbugs]

Thanks Janet. On the Roehampton site; Between those two (third paragraph on this page (185ENint) Entomobrya intermedia (Brook, 1884)), you'll find a quote that you didn't include...

I did expect the whole page to be read Jason! But put into context with the other paragraphs it means not a lot.

So, your whole new perspective on having to have a specimen and putting it under a microscope goes down the drain????

I'm afraid some people see what they want to see to the exclusion of all else, caution should be exercised.

I need to do other things just now, might post my pics later.

I have no intention of debating it either, I'll leave that to the experts out there! I believe intermedia does exist as a different species, and if you don't that's fine.

You already are debating it.

In my opinion, iit's a possible new species or even sub-species, and not an attempt to rescind intermedia as an entire species.

I don't think anyone suggested such an attempt, but to name it without a specimen?????

[Jason Green]

Originally Posted by JRsbugs

So, your whole new perspective on having to have a specimen and putting it under a microscope goes down the drain????

No, certainly not. Only when the two are pretty distinctly different, though as you acknowledge I would see no harm in double-checking from time to time!

Originally Posted by JRsbugs

I don't think anyone suggested such an attempt, but to name it without a specimen?????

He hasn't named it officially - more suggesting the format of the name as he sees it'll be should it be confirmed later on. The paragraph said:

Until specimens can be collected and examined it is not clear whether this is merely a colour variant or in fact a new species (an island endemic – Frans Janssens suggested E. intermedia "jerseyensis", but this name has no taxonomic validity at present.)

He's suggesting it's a sub-species over an entirely new one only, in my opinion - not attempting to name it without a specimen. See here - Springtail - Entomobrya intermedia "jerseyensis" on Flickr - Photo Sharing! - where you'll see him saying 'probaby', and then suggesting the collection of a voucher

Originally Posted by JRsbugs

You already are debating it.:

I was just summing up my views in that two-line paragraph.

Originally Posted by JRsbugs

I need to do other things just now, might post my pics later.

I'll look forward to it!

[JRsbugs]

Sorry, too late now to post pics so they will have to wait.

A couple of things I would like to reply to though..

Only when the two are pretty distinctly different, though as you acknowledge I would see no harm in double-checking from time to time!

Distinctly different? When the so-called E. intermedia keys out the same as E. nivalis? What about differences in pattern within a single species? There's many examples of Collembola which show very different colours and patterns, why is this being singled out as an exception? Perhaps you need to ask Frans Janssens if he has any scientific evidence which separates the two? What happened to scientific evidence? Do we now just go on how we think anything looks?

He hasn't named it officially - more suggesting the format of the name as he sees it'll be should it be confirmed later on.

I'm afraid I see this as putting the horse before the cart, and the horse could end up proving to be a donkey or ass. When it has been stated that the markings were "intermediate between E. intermedia and E. handschini", surely to make any sort of suggestion as to a name is heading in the same direction as putting a name to E. intermedia, oh yes it seems this is a favourite I forgot, favourite enough to invent a subspecies of an already very dubiously named species! Not at all scientific!

Can I be the only one to doubt all this, come on anyone else who has in the past spouted so much about naming without specimens, that is seemingly taboo even when a species is a known and accepted one. Taboo even if the obvious is obvious, so does this mean that if someone is recognised in a certain field they can get away with what they like? It has certainly happend in the past, leaving a world full of experts who have been duped with egg on their faces. Tristan where are you? Where is the voice of reason?

[Jason Green]

Hi all,

I've just heard back from Frans. He said:

I agree completely with Janet that the scientific approach is the only right one. Therefore, we need to stick to the facts. Science is based on facts and figures. Taxonomy is a dynamic 'science'. Every day new taxa are defined, existing taxa are 'deleted' (read: sunk to synonymy), or revised. The 'taxonomic debate' wrt E. intermedia is ongoing since its definition in 1884. The taxon has been defined by different taxonomists as species, as subspecies of other species, as intraspecific aberration, as synonym of other species. In the past it has often been lumped (together with other closely related species such as muscorum, multifasciata, nicoleti and lanuginosa) to nivalis by many different taxonomists. The elaborate revision of UK Entomobrya species of South (1961) eventualy settled for intermedia as valid species. This status was accepted in the authorative work of Christiansen & Bellinger (1980, 1998) on the Collembola of Northern America. At Checklist of the Collembola of the World we follow that opinion. And we can support that decission by the many photographic records from different locations in Europe and the USA, from which it is obvious that intermedia is morphologically different from nivalis. We have no knowledge of biological evidence that intermedia and nivalis are the same species (put otherwise: that they interbreed and produce offspring). There is also no genetic evidence (based on DNA research) that it are the same species.As long as there is no biological or genetic evidence we have to stick to the facts: that they are morphologically different and therefore different species.

I have also contacted Peter Shaw, so will update the thread when he replies.