When is a bumble's tongue long?

[laetoli]

I read in Edwards & Jenner's Field Guide to Bumblebees that Bombus pratorum has a short tongue. The individual in the above picture seems to me to have quite a long tongue. Apologies for the poor image quality. You can't see it here but the bee has an orange tail, which is one of the characteristics I've used to identify the species. Is this tongue in fact short, is this not B. pratorum or am I wrong in some other way that I haven't thought of yet?
Thanks,
Paul

[eucera]

All bumblebees have long tongues relative to, say, Andrena, Lasioglossum, Colletes. However, there is a clear gradation of lengths within Bombus.

I have looked at 15 studies which use Bombus tongue lengths and collated them into a spreadsheet.

Here are a few examples from the literature:
For reference, Apis has a TL of about 6.6mm
B. pratorum workers: between 7.1-8.8mm
B. pascuorum ww: 10.6-12.00mm
B. hortorum ww: 12.6-14.2mm
B. ruderatus ww: 14.7-15.3mm

So... the term as used by Mike & Martin is relative to other bumbles rather than relative to all bees.

I hope this helps a bit