M. leachella is a rare species that can be found mainly at the coast and in the most souther part of the Netherlands .
The species is active from May to August [2,3].
The female nests in existing cavities, like hollow stems or old bore holes in wood, or she digs a nest herself in sand ground with little growth, like a vertical wall. She covers the nest walls with cut leaves and fills the nest up with sand .
M. leachella is polylectic and uses the following plants as pollen source [3,4]:
|– Bird’s-foot trefoil (Lotus corniculatus)|
– Common restharrow (Ononis repens)
– Spiny restharrow (Ononis spinosa)
– Lucerne (Medicago sativa)
|Resedaceae||– Wild mignonette (Reseda lutea)|
Except for Spiny restharrow all these plants can be found in the garden.
3. PARASITIC RELATIONS
Sharp tailed bees (COELIOXYS) are primary parasites of M. leachella [3,4], they are cleptoparasites.
The following parasites cited in literature can be found in the Netherlands:
|– C. afra [3,4]|
– C. elongata [3,4]
– C. inermis [3,4]
– C. mandibularis [3,4]
– C. rufescens 
|– Monodontomerus obsoletus |
– Melittobia acasta 
I’ve observed Shapr tailed bees twice in the garden, but the species are not clear. In one of the observations it was either a female C. elongata or C. inermis.
The females and males of M. pilidens are difficult M. leachella. For an extensive description of the differences see .
1. White scopa 
2. Tergite 6 with two felt-like white hair spots 
3. Tergite 3 coarser puntated  – only difference with M. pilidens which has finer punctation 
4. Space between punctation more glossy and about as large as punctation .
5. Clypeus very shallow cut out 
1. Front tarsus darkbrown to black 
2. Front tarsus at most basally a little yellow-white, less heartshaped 
– only difference with M. pilidens
3. Coxa frontleg with clear thorn 
4. Tergites with white hairbands 
5. Tergite 6 entirely or partly with white hairs 
6. Femur frontleg hindside yellow coloured until the end
7. Sternite 4 has a hair spot at the end
References1 Nederlands Soortenregister