Andrena bicolor (Gwynne's mining bee)♀︎

Silene coronaria (Rose campion)

Last update: 5 February 2021
garden
species


Uncommon

LOCATION: Krimpen aan den IJssel, garden

OBSERVATION:


I saw this mining bee flying slowly and landing on Rose campion (Silene coronaria) to drink a sip and groom herself. I tried to approach her slowly but she quickly took off and vanished.

She is somewhat off because the hairs on the front of her face are light. After some digging I found this  paper on the Euandrena subgenus which includes species with the same superficial characters as the one in the photographs, among them some very rare species:

  1. A. bicolor (uncommon, hair seem to dark on head and side)
  2. A. ruficrus (uncommon, hindlegs are more yellow)
  3. A. fulvida (rare, no observations in the province Zuid-Holland)
  4. A. rufula (very rare, one observation, province Zuid-Holland)
  5. A. fulvata (very rare, seems restricted to the most southern province Limburg, the female can be misidentified for A. rufula)
  6. A. angustior (uncommon, hairs on thigh too white)

What doesn’t help is that my photographs are mediochre in quality and do not show details, especially on the face.
A number of experts looked at it on Waarneming forum and the end conclusion was that it probably is a lighter variant of A. bicolor, normally the face has darker to black hairs.
The alternatives did not match based on either appearance (2, 4, 6), location (5) or activity period (4).

I did some measurements around the ocelli and compared them to this specimen which matched A. angustior, however the expert indicated that this method is very unreliable especially when applied to photographs so it didn’t yield a result.

Oh well, it was some nice detective work and it gained me more knowledge.

Gwynne’s mining bee ♀︎ (Andrena bicolor sp. inc.) on Rose campion (Silene coronaria)
Gwynne’s mining bee ♀︎ (Andrena bicolor sp. inc.) on Rose campion (Silene coronaria)
Gwynne’s mining bee ♀︎ (Andrena bicolor sp. inc.) on Rose campion (Silene coronaria)
Gwynne’s mining bee ♀︎ (Andrena bicolor sp. inc.) on Rose campion (Silene coronaria)

Literature

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