Grey Mining Bees in Wanstead Park

Visiting the Temple in Wanstead Park on 11th April 2010, my attention was drawn to numbers of small bees that were busy about the slope leading up to the Temple's portico.

An attractive black and light-grey colour, with the wings giving a somewhat bluish tinge, they were burrowing into the somewhat sparsely-vegetated ground on the slope. After trawling through various identification guides, what I came up with was the Grey - or Ashy - Mining Bee Andrena cineraria, which is listed in the Essex Red Data List as "Vulnerable". The Red Data List consists of species that are classified into different categories of perceived risk.

Grey Mining Bees, Andrena cineraria

The photograph to the right was taken from directly above two bees, one above ground and the other just showing as a tail in a hole.

As there appeared to be only three areas within Essex from where these bees have been reported, I reported the find to Peter Harvey, the recorder for Hymenoptera in Essex. He sent an encouraging reply, saying that the only other modern records were also from the Epping Forest area, but all quite a bit further north. He also mentioned that there is another mining bee that looks similar, Andrena nigrospina, but this is only adult later in the season, late May and June. He suggested that the  discovery was worth a note in the Essex Field Club Newsletter or the Essex Naturalist.

The bees appear to have a very limited period when they are observable as adults, and this may have been the reason why they have not been recorded before - they have just been missed. This seemed to prove true when a return visit was made to the slope on 18th April. Only a few bees were present, and no holes were visible. The weather conditions were broadly the same - that is to say fine - although the visit was made a few hours earlier than last time, at 1pm instead of 4pm. But it is also true that the condition of the vegetation on the slope has changed within the last few years, with increased usage by humans as the Temple has been opened at weekends and the Temple grounds used for an increasing number of events. This may have led to thinning of the vegetative cover, giving the bees more of an opportunity to burrow.

The slope is home also to a rare plant in this area, Birdsfoot, Ornithopus perpusillus (photo), which is very low growing and perhaps may not be affected by the trampling. However another rare plant in the area which grows here is Harebell, Campanula rotundifolia (photo). This, I suspect, will not benefit from humanity in the same way as the bees may be doing!

Andrena cineraria photographed on 19th April 2009

Doing a search on the internet for Andrena cineraria a day after contacting Peter, I was surprised to find an entry; what was even more surprising was that it was my own - a record from 2009. I had photographed a bee that I hadn't seen before and had tentatively identified it as A. cineraria. However it was so tentative an identification that I'd forgotten it! That particular specimen was found a little further south in the Park than the Temple, on 19th April.

Paul Ferris, 18 April 2010