[ID] Andrena labialis?

[Jason Green]

Evening all,

I'm just going through a few of my collected+pinned Andrenidae mining-bee vouchers. So far mainly the usual plus one I remember keying-out to a possible Nb species. Then this one... keys confidently to Andrena labialis, which I believe is on a possible list for inclusion as a future UKBAP species.

Is my determination correct habitus-wise? Please excuse the setting method with the head on the samp plane - next year that and the fore-legs will be downward-drawn.

01/06/2011

DATA: 1st June 2011, potted from bank of earth, woodland/grassland-edge habitat

Any info on the species' current status would be appreciated. Thanks for looking!

Take care,

Jason

[Matt Smith]

It looks pretty good for a male Andrena labialis, the yellow on the face reduces the number of possibilities greatly. To be fully sure I'd really need to see a close up of the scuplture and puncture density on the mesonotum (top of the thorax) and the same for Tergite 1.

You can see a map for the species either via the BWARS site or directly from the NBN. Not sure about it a a possible BAP candidate - not heard that anywhere. Seems to have a preference for vetches as a pollen source.

[Jason Green]

The future inclusion in UKBAP came from it's entry on the Essex Field Club website, and I believe may be similarly-mentioned on the JNCC site. I wasn't aware it was potentially uncommon, but is said to have contracted it's range or something.

The determination was made using 50x magnification with a 20w halogen bulb. Very obvious microreticulation between mesonotal punctures, very long and erect silvery hairs on T2 (just visible in the lateral elevation in post #1), 15% too long for chrysosceles and the yellow lower paraocular area excludes humilis.

[Matt Smith]

Be careful of looking at differences in areas that aren't specified in a specifc couplet of the key. As an example I mean the lengths of the hairs you mention. If you are using the GE Andrena test key then the split of Andrena labialis (and others) from A.chrysoceles happens via the mesonotal surface character. All 3 species left in the key at this point have a microreticulate mesonotum, it is the puncture separation that is the key character at this point - viz:

Disc of mesoscutum with sparse punctures, punctures separated by a puncture width or more, plus tibial colour characters - A.chrysoceles

Disc of mesoscutum matt with dense punctures, separated at most by half a puncture width, plus tibial characters - A.humilis & A.labialis .

Although both couplets mention hair lengths, they are comparative lengths making reference to a distance on the body of the insect you are looking at (eg "less than half the depth of the marginal area") and are thus more "confirmatory" characters as they do not compare hair lengths between the two different halves of the couplet. Be wary of using such "confirmatory characters" like this - stick to way the key runs and only use the characters in the key in the way they are mentioned.

The "potential BAP species" mention on the Essex Field Club would appear to be very outdated, the page was last updated in March 2007. An awful lot of species were proposed as BAP species during the last review, though I don't recall seeing A.labialis on any of the lists I looked at. Whether it was or not, it didn't make the final cut and is not a current BAP species.