8x12mm (Not round). Where does that leave me ?
I had assumed that
M willughbiella was the statistical favourite, but they are mainly plant pot soil nesters. My bee is in bamboo.
M ligniseca may be worth a try. Twardhe description I have say 'pale golden hairs on abdomen, with black on last two segments' so that is about right.
Ever onward, and thanks. Mick.