One running mission of mine is to get the Blue mason bee (Osmia caerulescens)  to nest in the bee hotels. So far that has not happened yet, but this female was clearly busy building one.
She is gnawing a piece of Common mallow (Malva sylvestris) leaf, starting from the edge inwards, and it looks this isn’t the first time she has been on this leaf. She does not cut a well defined piece of leaf like leafcutter bees do but instead is sort of scraping the leaf material into a ball. The material is cut into a paste and used to make the bulkheads between the brood cells [2,3].
I’m keeping an eye on the hotels. Every now and then a female will be sitting in an opening but they seem to be resting a bit, not nesting.
References1 Nederlands Soortenregister
2 Breugel, P. van 2014. Gasten van bijenhotels. – EIS Kenniscentrum Insecten en andere ongewervelden & Naturalis Biodiversity Center, Leiden.
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