Unfortunately, I didn’t manage to take a photo of it, but I saw a small bumblebee that was all black apart from a well-defined white tail feeding on comfrey on Friday. I wonder if it might have been a hypnorum worker. Do they occur with a black thorax?
Well spotted James:- here is a paragraph from an article in Leicestershire Entomological Society’s Newsletter 49, September 2013, mentioning melanic B. hypnorums that were seen in VC55 .
“On 20 May 2011, Helen Ikin and Steve Woodward
found a bird nest box at Grace Dieu Manor Farm
SK437182 occupied by black bumblebees with white
tails. Mike Edwards [BWARS] identified them as Bombus
hypnorum, but strikingly different from the usual form
with the ginger thorax. This black form is not
mentioned in the field guides.”
[Although “Field Guide to the Bumblebees” - Edwards & Jenner - in “variability” mentions that some specimens are very dark.]
The usual colour form B. hypnorum queen that I thought was going to use one of my bird boxes, decided to go behind my neighbour’s roof guttering instead!
Thanks for that. I’ll keep an eye out for more melanistic ones when I’m next in that location. I have seen remarkable variation in colour in the thorax for hypnorum from quite pale yellow to rather dark brown, but not black - till now.
I agree that there is much variation in thorax colour for B. hypnorum. Black doesn’t surprise me. Chocolate brown is quite common.
The white tail fur would be the diagnostic feature.
The darkness can be accentuated by worn fur, particularly on the crown of the thorax, exposing the black of the carapace.
When I was a schoolboy, monks were said to have a hairstyle called a “tonsure” a bald crown of the head, but a ring of hair round the rest of the head. This describes what you see in B. hypnorum foragers and house bees very well.
I hope the above helps !
Do see if you can get a photo for us to see. Yours Clive