Osmia bicornis

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Osmiini
Genus: Osmia Panzer, 1806
Subgenus: O. (Osmia) Panzer, 1806
Species: Osmia bicornis Linnaeus, 1758
Common name: red mason bee or red mortar bee

Overview

Osmia (Osmia) bicornis are black bees with a metallic blue to blue-green shimmer (Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.). Females have black hair on their face, and two distinct horns projecting from their hairless clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
. They have brown-gray hair on T1–T3 and black hair on T4–T6 (Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.). Male hair coloration is similar to the females with exception of abundant whiteish-yellow hairs on their face and clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
, and T4–T7 have black hair. Female body length ranges from 8–12 mm; male body length is 8–12 mm (Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.).

Diagnostic characteristics 

(from Peters 1978Peters 1978:
Peters, D.S. 1978. Systematik und Zoogeographie der west-palauml;arktischen Arten von Osmia Panzer, 1806 s. str., Monosmia Tkalcu, 1974 und Orientosmia n. subgen. (Insecta: Hymenoptera: Megachilidae). Senckenbergiana Biologica (Frankfurt) 58: 287ndash;346.; Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.)

• Mouthparts much smaller than the length of the entire body when extended.
• Terga terga:
  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
  without apicalapical:
  near or at the apex or end of any structure
  hair bandsbands:
  usually referring to bands of hair or bands of color that traverse across an abdominal segment
  .
• Female clypeusclypeus:
  a section of the face below the antennae, demarcated by the epistomal sutures
  with long laterallateral:
  relating, pertaining, or attached to the side
  horns and a flat, 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
  median apicalapical:
  near or at the apex or end of any structure
  projection.
• Female clypeusclypeus:
  a section of the face below the antennae, demarcated by the epistomal sutures
  without a median longitudinal ridge.
• Male clypeusclypeus:
  a section of the face below the antennae, demarcated by the epistomal sutures
  with a small median apicalapical:
  near or at the apex or end of any structure
  notch.
• Male gonocoxites not noticeably swollen at preapicalpreapical:
  referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
  angle.
• 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
  with a clear basalbasal:
  originating at the foundation of a structure
  gradulus.

May be confused with 

Osmia bicornis look similar to O. rufina and O. pedicornis. Females of these species all have laterallateral:
relating, pertaining, or attached to the side
horns and bidentatebidentate:
having two teeth
median apicalapical:
near or at the apex or end of any structure
projection on the clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
. O. rufina females can be differentiated by the shape of the median apicalapical:
near or at the apex or end of any structure
projections on the clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
and the long, non-bifurcate laterallateral:
relating, pertaining, or attached to the side
horns on the clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
. Males are similar in size and hair color and can be difficult to distinguish without dissecting them to see the genitaliagenitalia:
all the genital structures collectively
and hidden sternasterna:
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
. They can, however, be distinguished by the shape of S8S8:
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
and the apexapex:
end of any structure
of the gonocoxites.

Phenology

Osmia bicornis adults have been recorded in flight from March to July (Banaszak and Romasenko 1998Banaszak and Romasenko 1998:
Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Bydgoszcz University, Bydgoszcz, Poland.; Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.).

Host associations 

Osmia bicornis are generalists and have been observed pollinating a variety of plant species (Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.). They do, however, seem to prefer plants within the Rosaceae and Fabaceae families (Banaszak and Romasenko 1998Banaszak and Romasenko 1998:
Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Bydgoszcz University, Bydgoszcz, Poland.). O. bicornis are also especially efficient at pollinating apple and some crops grown within greenhouses (Krunic et al. 1995Krunic et al. 1995:
Krunic, M., M. Pinzauti, A. Felicioli, and L. Stanizavljevic. 1995. Further observations on Osmia cornuta Latr. and O. [Osmia] rufa L. as alternative fruit pollinators, domestication and utilization. Food and Agricultural Organization of the United Nations 47: 59ndash;66.).

Nesting behavior 

Osmia bicornis nest in a wide variety of preexisting cavities including wooden buildings, pithy or hollow stems, thatched roofs, snail shells, and man-made artificial nests (Banaszak and Romasenko 1998Banaszak and Romasenko 1998:
Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Bydgoszcz University, Bydgoszcz, Poland.). Cells are usually arranged linearly in deep narrow cavities but are sometimes laid flat or in multiple rows in shallow wide cavities (Banaszak and Romasenko 1998Banaszak and Romasenko 1998:
Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Bydgoszcz University, Bydgoszcz, Poland.; Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.; Ivanov 2006Ivanov 2006:
Ivanov, S.P. 2006. The nesting of Osmia rufa (L.) (Hymenoptera, Megachilidae) in the Crimea: Structure and composition of nests. Entomological Review 86: 524ndash;533.). Cell partitions and nest plugs are comprised of moistened soil or clay (Banaszak and Romasenko 1998Banaszak and Romasenko 1998:
Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Bydgoszcz University, Bydgoszcz, Poland.).

Distribution

Osmia bicornis specimens have been recorded across Europe, northern Africa, and western Asia (Amiet et al. 2004Amiet et al. 2004:
Amiet, F., M. Herrmann, A. Mueller, and R. Neumeyer. 2004. Apidae 4: Anthidium , Chelostoma , Coelioxys , Dioxys , Heriades , Lithurgus , Megachile , Osmia , Stelis . Fauna Helvetica 9: 1ndash;273.).

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References

Banaszak, J. and L. Romasenko. 1998. Megachilid bees of Europe (Hymenoptera, Apoidea, Megachilidae). Pedagogical University Bydgoszcz, 239 pp.

Ivanov, S.P. 2006. The nesting of Osmia rufa (L.) (Hymenoptera, Megachilidae) in the Crimea: structure and composition of nests. Entomological Review 86: 524-533.

Krunic, M., M. Pinzauti, A. Felicioli, and L. Stanizavljevic. 1995. Further observations on Osmia cornuta Latr. and O. [Osmia] rufa L. as alternative fruit pollinators, domestication and utilization. Food and Agricultural Organization of the United Nations 47: 59-66.

Peters, D.S. 1978. Systematik und zoogeographie der west-paläarktischen arten von Osmia Panzer 1806 s. str. Monosmia Tkalcu 1974 und Orientosmia n. subgenera (Insecta: Hymenoptera: Megachilidae). Senckenbergiana Biology 58: 287-346.

Scheuchl, E. 2006. Illustrierte Bestimmungstabellen der Wildbienen Deutschlands und Österreichs. Vol. 2, Megachilidae-Melittidae. Erwin Scheuchl und Apollo Books, 116 pp.