|MULLER, ANDREAS - Eth Zurich|
Submitted to: Zootaxa
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2017
Publication Date: 11/29/2017
Citation: Muller, A., Griswold, T.L. 2017. Osmiine bees of the genus Haetosmia (Megachilidae, Osmiini): Biology, taxonomy and key to species. Zootaxa. 4358(2):351–364. http://dx.doi.org/10.11646/zootaxa.4358.2.8.
Interpretive Summary: Among the sixteen genera of the mason bees, tribe Osmiini, the genus Haetosmia is one of the smallest with only three species previously known, all of them restricted to the Canary Islands and the northern coast of Africa or Turkey east to Afghanistan. Here we double the known species by describing two new species and elevating one subspecies to species rank. The new species and new records for previously described species expand the range of this genus to include the Sahel of Africa, east Africa from Ethiopia to Tanzania, the Arabian Peninsual, and Central Asia. All of the species are believed to harvest pollen only from narrow-tubed flowers of plant genus Heliotropium (Boraginaceae). To extract the pollen from the narrow tubes of the flowers they use specialized pollen-harvesting bristles on the tongue. What we know about the distributions of these bees suggests that Haetosmia is restricted to sandy habitats, excavates their nests in the ground, and uses chewed leaves to construct the urn-shaped pockets they make for their offspring. These pockets are placed side by side in an enlarged chamber at the end of the nest tunnel.
Technical Abstract: Haetosmia is a species-poor genus of osmiine bees (Megachilidae) containing six species, which inhabit deserts and semideserts between the Canary Islands and Central Asia. Formerly considered to be restricted to the southern Palaearctic region, the genus is shown here to occur also in the northern Afrotropical region. The females of all six Haetosmia species collect pollen most probably exclusively on the narrow-tubed flowers of Heliotropium (Boraginaceae) with the aid of specialized pollen-harvesting bristles on the proboscis. Current knowledge suggests that the Haetosmia species are restricted to sandy habitats, excavate their nests in the ground and use chewed leaves to construct their urn-shaped brood cells, which are placed side by side in an enlarged chamber at the end of the nesting burrow. The taxonomic revision of Haetosmia revealed the existence of two still undescribed species, i.e. H. ethiopiensis spec. nov. from eastern Africa and H. pakistaniensis spec. nov. from Pakistan. Due to clear morphological gaps and overlapping distribution areas, the two subspecies H. brachyura altera (Peters, 1974) and H. brachyura brachyura (Morawitz, 1875) are newly elevated to species rank. Keys for the identification of the six Haetosmia species are given.