Excavator: Ground. Excavated burrows in hard and generally horizontal soil (ca. 2-3cm deep) with 1-3 linearly arranged cells. Nesting material: The cells are entirely built of several layers of petals of Convolvulus (occasionally Papaver). Petals of Convolvulus are also used to build partitions between adjacent cells and to line the entrance burrow. The nest entrance is filled with sand in the end. (Benoist, 1931; Ferton, 1894, 1895, 1897, 1901, 1908; Ducke, 1900; A. Müller, personal observation; Müller & Richter, 2018)