Hylaeus mirandus (Rayment, 1930); Hylaeus multigibbosus Michener, 1965; Hylaeus (Rhodohylaeus) Michener, 1965 Hylaeus (Sphaerhylaeus) Cockerell, 1929 Hylaeus (Xenohylaeus) Michener, 1965 Asia China 21 species have been formally identified and described in China. These are as follows: Hylaeus (Dentigera) luna, Hylaeus asiaticus, Hylaeus difformis, Hylaeus dolichocephalus, Hylaeus dorni, Hylaeus fuliginosus, Hylaeus mongolicus, Hylaeus niger, Hylaeus paulus, Hylaeus perforatus, Hylaeus potanini, Hylaeus przewalskyi, Hylaeus sibiricus, Hylaeus sinensis, Hylaeus medialis, Hylaeus pfankuchi, Hylaeus floralis, Hylaeus concinnus, Hylaeus nigricallosus, Hylaeus confusus and Hylaeus variegatus. Japan 23 species of Hylaeus are formally identified in Japan. Saudi Arabia Only one species of Hylaeus has been formally recorded in Saudi Arabia - Hylaeus (Paraprosopis) albonotatus. Further surveying of bee fauna is likely to result in further groups being recorded, due to the close proximity of numerous other species and subgenera of Hylaeus. Ecology Nesting Biology Hylaeus nests in premade holes and prefers to nest in wood, but will nest in dead stems, rocks, and earthworm burrows. When a suitable premade hole is found, it is then divided by transverse partitions of clear cellophane-like material. The inner most cell is the one farthest from the nest entrance, and is characterised by a round distal end in order to fit the hole. Cell volumes are more or less constant. Lateral burrows are not constructed in this genus, but cells are placed end to end in the main nest. Hylaeus lines their nest with a waterproof and contaminant proof clear cellophane substance that does not melt or dissolve with strong chemicals. They also secrete a substance that protects the nest from fungi and bacteria. This substance is secreted from the mandibles. Food mass placed in cells is liquid, even watery in some cases. It fills the bottom part of the water-proof cells. This liquid state is due a relatively small amount of pollen deposited in it from the crop. This pollen is then placed in a nectar admixture. Diet and Feeding Females gather large amounts of nectar for their semi-liquid provisions, and males feed on nectar. Observations suggest that Hylaeus are specialized in terms of pollen they collect, and near exclusively line their cells with pollen from plants they are specially adapted to. Pollen is carried internally in the crop. Pollen-grooming movements by this genus to get pollen to the mouth only take pollen from the head and forelegs, with pollen on other parts of the body being lost. It