Osmia (Trichinosmia)


Family: Megachilidae
Subfamily: Megachilinae
Tribe: Osmiini
Genus: Osmia Panzer, 1806
Subgenus: Trichinosmia Sinha, 1958
Common name: none


Osmia (Trichinosmia) are green metallic bees with long, branched mixed black and white hairs on the head and thorax. They range in body length from 9–10 mm (Michener 2007).

Diagnostic characteristics

(modified from Michener 2007)

  • Forewing with hairs about as half as long as the width of the stigma.
  • Head and thorax are covered in long branched hairs.
  • Hind coxa without strong longitudinal carina along inner ventral angle.
  • Parapsidal line punctiform.
  • Female clypeal margin with strong lateral teeth and small median tooth.
  • Male antenna with middle flagellar segment two times as long as wide.
  • Male S2 large and convex, often covering S3 at least medially.

May be confused with

Osmia (Trichinosmia) can look similar to some species of O. (Melanosmia) but can be distinguished by abundant long, branched hairs on the head and thorax, and long hairs on their wings (Michener 2007).

Host associations

A study examining the pollen provisions in nest cells of O. latisulcata suggests that this species is oligolectic on Astragalus (Parker 1984).

Nesting behavior

In a study on Osmia (Trichinosmia), Parker (1984) observed O. latisulcata nesting in drilled holes in wood blocks. The cell partitions were constructed out of pebbles and masticated leaf pulp. This suggests that Osmia (Trichinosmia) nests in cavities; however, the types of cavities they use for nesting in nature is currently unknown.


Osmia (Trichinosmia) is monotypic with only one described species, O. latisulcata (Michener 2007).


Osmia (Trichinosmia) occur in desert or semi-desert areas in southwestern U.S. (Michener 2007).

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

<p><em>Osmia latisulcata </em>female face. Photo: Chelsey Ritner</p>
Osmia latisulcata female face. Photo: Chelsey Ritner
<p><em>Osmia latisulcata </em>female lateral habitus. Photo: Chelsey Ritner</p>
Osmia latisulcata female lateral habitus. Photo: Chelsey Ritner
<p><em>Osmia latisulcata </em>female abdomen. Photo: Chelsey Ritner</p>
Osmia latisulcata female abdomen. Photo: Chelsey Ritner