Osmia (Helicosmia)

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Osmiini
Genus: Osmia Panzer, 1806
Subgenus: Helicosmia Thomson, 1872
Common name: none

Overview

Osmia (Helicosmia) are metallic blue or green bees (although occasionally not metallic or only faintly so) with pale hairs on their head, thorax, and abdomen. They can have black or white scopal hairs and typically possess pale apicalapical:
near or at the apex or end of any structure
fasciae on their tergaterga:
the segments on the top side of the abdomen, often abbreviated when referring to a specific segment to T1, T2, T3, T4, T5, T6, or T7
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). They range in body length from 7.5–15 mm (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Diagnostic characteristics

(modified from Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.)

• Propodeum propodeum:
  the last segment of the thorax
  surface is dull.
• Hind coxacoxa:
  the basal segment of the leg
  without strong longitudinal carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  along inner ventralventral:
  of, on, or relating to the underside of an animal, or segment of an animal
  angle.
• Female clypeal margin usually with orange hairs beneath the rim of the clypeusclypeus:
  a section of the face below the antennae, demarcated by the epistomal sutures
  arranged into four tufts. In rare cases, they may be absent or not distributed into tufts.
• Female mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  robust, with depression across base that is abruptly set off from adjacent mandibularmandibular:
  near the mandible
  surface.
• Male S2S2:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  large and apicallyapically:
  near or at the apex or end of any structure
  convex.
• Male S3S3:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  medially emarginateemarginate:
  a notched or cut out place in an edge or margin, can be dramatic or simply a subtle inward departure from the general curve or line of the margin or structure being described
  , emarginationemargination:
  a notched or cut out place in an edge or margin, can be dramatic or simply a subtle inward departure from the general curve or line of the margin or structure being described
  largely hidden by enlarged S2S2:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  .
• Male S4S4:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  apicalapical:
  near or at the apex or end of any structure
  margin has two carinae laterally with a narrow, hairless, shiny groove between them.
• Male S6S6:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  lacks longitudinal groove and lacks a projecting lobe.
• Male T7T7:
  the segments on the top side of the abdomen, often abbreviated when referring to a specific segment to T1, T2, T3, T4, T5, T6, or T7
  has a small midapical emarginationemargination:
  a notched or cut out place in an edge or margin, can be dramatic or simply a subtle inward departure from the general curve or line of the margin or structure being described
  or is bidentatebidentate:
  having two teeth
  .

May be confused with

Osmia (Helicosmia) may be confused with O. (Diceratosmia) and O. (Pyrosmia) due to similar grooved margins of S4S4:
the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
in males and the presence of apicalapical:
near or at the apex or end of any structure
tergal fasciae of plumoseplumose:
feather-like
hairs (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). However, O. (Helicosmia) can be differentiated from the two other subgenera due to the characteristics listed above.

Host associations

Osmia (Helicosmia) have been observed visiting Fabaceae, Boraginaceae, Lamiaceae, Antirrhineae, Asteraceae, Hypericaceae, Brassicaceae, Ranunculaceae, Carduoideae, Cistaceae, Polygalaceae, and Antirrhineae (Banaszak and Romasenko 1998Banaszak and Romasenko 1998:
Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Bydgoszcz University, Bydgoszcz, Poland.; Grace 2010Grace 2010:
Grace, A. 2010. Introductory biogeography to bees of the eastern Mediterranean and Near East. Bexhill Museum, Sussex, United Kingdom.; Müller 2018).

Nesting behavior

Osmia (Helicosmia) nests predominantly in preexisting cavities such as holes in wood, stems, and abandoned insect burrows (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Müller 2018). Cell partitions and nest plugs are made of masticated leaf materials and sometimes chewed flower petals (Müller 2018).

Osmia (Helicosmia) melanogaster have been observed nesting in abandoned snail shells, in fissures in stone walls, insect burrows in dead wood, and hollow stems (Banaszak and Romasenko 2001Banaszak and Romasenko 2001:
Banaszak J. and L. Romasenko. 2001. Megachilid bees of Europe. Second edition. Bydgoszcz: Bydgoszcz University Press. 239 pp.; Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Müller 2018).

Osmia dimidiata nest in hollow stems and abandoned cells in nests of other bees. Nests are linear, and generally contain 1–2 cells, but can have as many as 9 brood cells (Ivanov et al. 2013Ivanov et al. 2013:
Ivanov, S.P., A.V. Fateryga, and M.A. Kobetskaya. 2013. The nesting biology of the bee, Osmia dimidiata Morawitz, 1870 (Hymenoptera, Megachilidae) in the Crimea. Entomological Review 93: 675ndash;694.).

Osmia (Helicosmia) heteracantha nest in insect burrows in the ground and in abandoned cells from exposed Hoplitis nests (Müller 2018).

Osmia orientalis nest in snail shells, with up to 10 cells per shell. Cell partitions are constructed of masticated leaves and are not fully closed except for the outer partition. The last cell partition is thick, complete, and acts as the nest plug (Maeta 1978Maeta 1978:
Maeta, Y. 1978. Comparative studies on the biology of the bees of the genus Osmia of Japan, with special reference to their managements for pollinations of crops (Hymenoptera: Megachilidae). Bulletin of the Tohoku National Agricultural Experiment Station. 57: 195ndash;209.; Kandori et al. 2010Kandori et al. 2010:
Kandori, I., M. Tamaru, and T. Yokoi. 2010. Nesting habits of a pollinator: Osmia orientalis (Hymenoptera: Megachilidae). Japanese Journal of Applied Entomology and Zoology 54: 77ndash;84.; Müller 2018).

Osmia aurulenta also nest in snail shells, with up to 17 cells arranged side by side with leaf pulp. The shell surface is covered with leaf pulp and left alone (no turning or moving) after the nest is closed (Westrich 1989Westrich 1989:
Westrich, P. 1989. Die Wildbienen Baden-Wuuml;rttembergs. Eugen Ulmer GmbH amp; Co., Stuttgart, 972 pp.; Müller et al. 1997; Banaszak and Romasenko 2001Banaszak and Romasenko 2001:
Banaszak J. and L. Romasenko. 2001. Megachilid bees of Europe. Second edition. Bydgoszcz: Bydgoszcz University Press. 239 pp.; Müller 2018).

Osmia fasciata nests in abandoned burrows and brood cells of an Amegilla bee species that nests in steep, hard-packed, sandy slopes. Cells are arranged linearly and are built from chewed leaves (Müller 2018).

Diversity

Osmia (Helicosmia) consists of 72 described species with at least 1 undescribed species (Müller 2018). There are 5 known species that occur in North America.

Known invasives

Osmia caerulescens is native to Europe, the Middle East, Asia, and North Africa. They were introduced to North America from Europe in the 1800s and now occurs throughout the eastern half of the U.S. (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Russo 2016Russo 2016:
Russo, L. 2016. Positive and negative impacts of non-native bee species around the world. Insects 7: 69.).

Distribution

Osmia (Helicosmia) occur throughout North America to Mexico, and throughout Europe, northern Africa, the Mediterranean Basin, and Asia (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Müller 2018).

​Distribution map generated by Discover Life -- click on map for details, credits, and terms of use.

References

Banaszak, J. and L. Romasenko. 1998. Megachilid Bees of Europe. Pedagogical University of Bydgoszcz, Poland, 239 pp.

Banaszak J. and L. Romasenko. 2001. Megachilid bees of Europe. Second edition. Bydgoszcz: Bydgoszcz University Press. 239 pp.

Grace, A. 2010. Introductory biogeography to bees of the Eastern Mediterranean and Near East. Bexhill Museum Association, 283 pp.

Ivanov, S.P., A.V. Fateryga, and M.A. Kobetskaya. 2013. The nesting biology of the bee, Osmia dimidiata Morawitz, 1870 (Hymenoptera, Megachilidae) in the Crimea. Entomological Review 93: 675-694.

Kandori, I., M. Tamaru, and T. Yokoi. 2010. Nesting habits of a pollinator: Osmia orientalis (Hymenoptera: Megachilidae). Japanese Journal of Applied Entomology and Zoology 54: 77-84.

Maeta, Y. 1978. Comparative studies on the biology of the bees of the genus Osmia of Japan, with special reference to their managements for pollinations of crops (Hymenoptera: Megachilidae). Bulletin of the Tohoku National Agricultural Experiment Station. 57: 195–209. 

Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.

Müller, A., A. Krebs, and F. Amiet. 1997. Bienen: Mitteleuropäische Gattungen, Lebensweise, Beobachtung. Naturbuch Verlag, Augsburg, pp. 384.

Müller, A. 2018. Palaearctic Osmiine Bees, ETH Zürich, http://blogs.ethz.ch/osmiini

Westrich, P. 1989. Die Wildbienen Baden-Württembergs. Eugen Ulmer GmbH & Co., Stuttgart