1

Re: Bombus lucorum aggregation

I hope this hasn't been covered already, but I couldn't find a thread about it.  Apologies in advance if it has.

I have been informed that ( and read a report about) with certain Bombus species, it has been shown that visual identification, even using queens, is unreliable.  This specifically applies to the species B. lucorum, B. cryptarum, and B. magnus (i.e. the B lucorum complex), and an ID cannot be properly determined except via a DNA analysis.

However, Recorder 6 has a taxon dictionary structured such that the above 3 species are within the sub-genus "Bombus", as well as B. terrestris.  Therefore I cannot accurately log any of my recent observations as either of the 3 species in the B. lucorum complex, but nor can I record it as simply belonging to the sub-genus Bombus, since that implies it could be B. terrestris as well.

Therefore, how do I record my observations?

Thanks
Nigel

2

Re: Bombus lucorum aggregation

It is even worse than that, Nigel, as is is not even certain that these are the only species in the lucorum complex.

I can't understand why people get so worked up about this, as it is by no means the only situation where species can't be identified in the field (and sometimes not even with a body), and we don't get dipterists for example suffering the same angst.  The Bombus business has led to the idiotic 'terrestris/lucorum' pseudotaxon, which has no justification in science and sets a precedent for an infinity of other pseudotaxa (except that in most cases difficulties are managed in a rather more sensible fashion).

B. terrestris is easy (apart from some workers), so record it as the species.

For 'lucorum', the sky will not fall on your head if you just don't record it at all, or if you must record it then do it at the genus and add an appropriate comment.

Murdo

3

Re: Bombus lucorum aggregation

Thanks for your comments, Murdo.
Whilst I go along with the gist of your reply, I am unhappy about the idea of not recording, since if that were widely replicated, then changes in distributions/numbers would not be noted.

I did wonder about simply carrying on as before (well, the historic data is in that state - not tested by DNA).  And if any properly verified observations are made by people, then that can be logged in Recorder.  In that way, there will be a distinction between the rock-sold data, and that which is potentially still useful.  Otherwise, it will be like throwing away the baby with the bath water.

Regards
Nigel

4

Re: Bombus lucorum aggregation

Hi Nigel,

Quite a lot has already been said in this thread: http://forums.nbn.org.uk/viewtopic.php?id=1983

It can be quite hard to find previous relevant threads!

Mike Beard
Natural Course Project Officer
Greater Manchester Local Records Centre

5

Re: Bombus lucorum aggregation

Hello Mike
Yes, I had seen that post.  But it doesn't solve my problem.

I would rather continue the practice of recording within B lucorum s.l. group where possible, as appearing to be a particular species, but with the caveat that it "looks like magnus", or "looks like cryptarum", or whatever.  That has effectively been the regime that has operated, until the knowledge now that this is inaccurate, and cannot be accepted.  Recording it at the genus level will be a step backwards, and I don't see the point in doing that.

Regards
Nigel

6 (edited by Syrphus 09-04-2012 11:11:35)

Re: Bombus lucorum aggregation

I don't see, Nigel, how recording accurately at genus level can possibly be regarded as a step backward from recording inaccurately at species level.  We have no idea what the species limits are in 'Bombus lucorum' - neither how many cryptic species we have, nor what the morphological correlates are.

Until the dictionary is updated to include the B. lucorum aggregate, the only sensible option is to go for genus.  There are currently two idiotic pseudotaxa in the List of additional names which you can use if you want, but no-one should  give these any credibility at all.  They indicate nothing except that some species cannot be reliably distinguished in the field.  This is nothing new, and not confined to Bombus.

M.

7

Re: Bombus lucorum aggregation

Okay Murdo.  I guess I'll have to go with that.

Nigel