Archive for the ‘Biology’ Category

Nests of seven osmiine bee species detected for the first time

Wednesday, June 6th, 2012

On their excursion to Tunisia in spring 2012, C. Sedivy, C. Praz and A. Müller detected the hitherto unknown nests of Hoplitis (Annosmia) hierichonicaHoplitis (Anthocopa) albiscopa, Hoplitis (Anthocopa) sinuataHoplitis (Pentadentosmia) villiersi, Osmia (Helicosmia) heteracanthaOsmia (Neosmia) scutispina and Osmia (Pyrosmia) derasa. For details see the species accounts on the Palaearctic osmiine bee website.

American Osmia species with modified facial bristles for pollen uptake

Wednesday, December 28th, 2011

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.

Nest of Osmia distinguenda discovered for the first time

Friday, September 30th, 2011

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).

Specialized pollen-harvesting device in Erythrosmia

Friday, July 1st, 2011

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).

Pollen hosts of Osmia nasoproducta

Friday, April 15th, 2011

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.

New results of pollen analytical studies 3

Tuesday, January 25th, 2011

Results of the microscopical analysis of 350 pollen samples from about 110 osmiine bee species were incorporated into the species accounts. For the following 6 species, the first pollen samples became available: Hoplitis (Alcidamea) decaocta, Hoplitis (Annosmia) fulica, Hoplitis (Annosmia) gentilis, Hoplitis (Annosmia) eremophila, Hoplitis (Anthocopa) antigae, Osmia (Hemiosmia) chrysolepta.

Nesting biology of Hoplitis (Annosmia)

Monday, January 10th, 2011

In a recent paper, Le Goff (2010) describes the nest architecture of Hoplitis (Annosmia) annulata and Hoplitis (Annosmia) tkalcuella. For details see the species accounts on the Palaearctic osmiine bee website.

Osmia croatica nests in empty snail shells

Friday, August 6th, 2010

The nesting behaviour of Osmia (Hoplosmia) croatica (Friese, 1893) was unknown so far. Recently, A. Müller detected a nest of this species in an empty snail shell hidden below stones in the Abruzzi mountains (Italy). For details see the species account on the Palaearctic osmiine bee website.

Nests of four osmiine bee species detected for the first time

Wednesday, June 23rd, 2010

On their excursion to Israel in spring 2010, C. Praz and C. Sedivy detected the hitherto unknown nests of Hoplitis (Anthocopa) batyamae, Hoplitis (Pentadentosmia) helouanensis, Hoplitis (Pentadentosmia) quinquespinosa and Osmia (Helicosmia) fasciata. For details see the species accounts on the Palaearctic osmiine bee website.

New results of pollen analytical studies 2

Sunday, May 30th, 2010

Results of the microscopical analysis of 254 pollen samples from 78 osmiine bee species were incorporated into the species accounts. For the following 8 species, the first pollen samples became available: Hoplitis (Annosmia) christae, Hoplitis (Annosmia) leiocephala, Hoplitis (Annosmia) segura, Hoplitis (Annosmia) verhoeffi, Hoplitis (Anthocopa) unispina, Hoplitis (Hoplitis) tkalcuella, Hoplitis (Pentadentosmia) enslini and Hoplitis (Pentadentosmia) helouanensis.