The biology of the two Hoplitis species of the subgenus Tkalcua was entirely unknown so far. On their excursion to Fuerteventura in spring 2015, V. Mauss and A. Müller detected nests of H. (Tkalcua) zandeni in empty snail shells. For details see the species account on the Palaearctic osmiine bee website.
G. Le Goff discovered the hitherto unknown nests of Hoplitis (Anthocopa) zaianorum and Hoplitis (Hoplitis) tenuiserrata in southern Morocco in spring 2013. For details see the species accounts on the Palaearctic osmiine bee website.
In a recent paper by Gotlieb et al. in American Museum Novitates (3808, 1-20, 2014), nests, floral preferences and immatures of Haetosmia vechti are described. Interestingly, H. vechti was found in Israel to nest in excavated burrows in sandy soil and to build urn-shaped brood cells from masticated leaves.
A recent paper in the Biological Journal of the Linnean Society by Haider et al. (2013) report on the host range evolution in Osmia bees of the subgenera Monosmia, Osmia and Orientosmia.
Two recent papers in the Biological Journal of the Linnean Society by Sedivy et al. report on the host range evolution (108, 35-54, 2013) and the evolution of nesting behaviour and kleptoparasitism (108, 349-360, 2013) in a species-rich clade of Hoplitis bees, the Annosmia-Hoplitis group.
On their excursion to Tunisia in spring 2012, C. Sedivy, C. Praz and A. Müller detected the hitherto unknown nests of Hoplitis (Annosmia) hierichonica, Hoplitis (Anthocopa) albiscopa, Hoplitis (Anthocopa) sinuata, Hoplitis (Pentadentosmia) villiersi, Osmia (Helicosmia) heteracantha, Osmia (Neosmia) scutispina and Osmia (Pyrosmia) derasa. For details see the species accounts on the Palaearctic osmiine bee website.
In a recent paper, Rightmyer et al. (2011) describe two new Osmia species from the southeastern United States belonging to the subgenera Melanosmia and Diceratosmia, respectively, which both possess a specialized facial pilosity composed of short and erect bristles. These bristles are used to collect pollen from nototribic flowers. At least six other Osmia species from North America have modified facial hairs, which probably have the same function (Rightmyer et al., 2011). In the Palearctic osmiine bees, a specialized facial pilosity used to collect pollen from the nototribic flowers of Lamiaceae and Antirrhineae is known to date from twelve species of Osmia (Helicosmia), four species of Osmia (Erythrosmia), three species of Hoplitis (Micreriades) and one species of Hoplitis (Hoplitis). Thus, morphological specializations for exploiting nototribic flowers have independently evolved many times in the osmiine bees.
In May 2011, G. Pisanty observed several females of Osmia (Hoplosmia) distinguenda nesting in small rock cavities in Israel (see species account for details). While Hoplosmia species of the spinulosa and the pinguis group all seem to exclusively nest in empty snail shells, the species of the bidentata group also use other nesting sites, such as hollow stems, insect borings in dead wood or rock cavities as now observed for O. distinguenda (photo by G. Pisanty).
The females of all four species of the subgenus Erythrosmia are equipped with a specialized facial pilosity composed of curved bristles. As has been observed in Osmia andrenoides (Müller, 1996b), this facial pilosity serves to remove pollen from nototribic anthers of Lamiaceae and Antirrhineae. In fact, nototribic flowers are important pollen sources of all four Erythrosmia species (see species accounts for details).
Osmia nasoproducta is a rare southwestern mediterranean bee whose biology is virtually unknown. Ivo Raemakers observed numerous females of this species collecting pollen on Cistus flowers near Perpignan in spring 2010, which is in line with recent observations made by A. Müller in the Alpilles, where several females visited the flowers of Cistus. As the few pollen samples analysed so far also contain small amounts of Asteraceae and Lamiaceae pollen, Osmia nasoproducta is probably not a Cistaceae oligolege. It appears, however, to have a strong preference for Cistus flowers, which might explain why this species is so rarely found.