Ashmeadiella

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Osmiini
Genus: Ashmeadiella Cockerell, 1897
Subgenera: Arogochila, Ashmeadiella, Chilosima, Cubitognatha, Isosmia
Common name: none

Overview

Ashmeadiella are nonmetallic, robust bees that range in length from 3.5–9.5 mm. They have a black head and thorax. Their abdomens can be black to entirely red with apical bands of white hairs on their terga (Michener 2007).

Diversity

Ashmeadiella contains approximately 60 species (Hurd and Michener 1955).

Diagnostic characteristics

(modified from Michener 2007)

May be confused with

Hoplitis and Atoposmia look similar to Ashmeadiella. However, Ashmeadiella differ from these two genera in that S2 and S3 of the males are subequal, whereas S2 and S3 in Hoplitis and Atoposmia are distinctly different in size (Michener 2007). Ashmeadiella (except for the subgenus Isosmia) can also be distinguished by the presence of an omaular carina (Michener 2007).

Known invasives

There are no known invasives.

Host associations

Many species of Ashmeadiella visit a wide variety of flowers, but some species exhibit some degree of floral specialization. For example, A. bucconis and A. californica visit Compositae flowers, whereas A. opuntiae specializes on Cactaceae, and A. prosopidis prefers Prosopis flowers (Michener 1939). The subgenus Isosmia appears to specialize on Dalea (Yanega 1994).

Nesting behavior

Ashmeadiella are solitary bees which utilize naturally occurring cavities in wood, soil, stems, or spaces under rocks to build their nests in (Michener 2007). In one case, an Ashmeadiella nest was found in the fuel line tubing of a crashed airplane (Rozen and Eickwort 1997). Nest partitions consist of masticated leaf pulp bound with nectar, resin, sap, or gum (Rozen 1987). Ashmeadiella rubella lines its nest with flower petals of Dalea spp. (Yanega 1994); A. holtii excavates its own subterranean nests by reinforcing the walls of the cell with a mixture of soil and nectar instead of plant material (Rozen 1987).

Distribution

Ashmeadiella are endemic to North America, ranging from southern Canada to Yucatan, Mexico (Michener 1944). Most species of Ashmeadiella are found in the western U.S., in mesic and desert environments. Only two species are known to be established east of the Mississippi, A. bucconis and A. floridana. Ashmeadiella bucconis has a transcontinental distribution, while A. floridana has only been found in the southeastern U.S (Michener 1939).

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

<p><em>Ashmeadiella californica</em> female face, photo: C. Ritner</p>
Ashmeadiella californica female face, photo: C. Ritner
<p><em>Ashmeadiella californica</em> female lateral habitus, photo: C. Ritner</p>
Ashmeadiella californica female lateral habitus, photo: C. Ritner
<p><em>Ashmeadiella californica</em> female abdomen, photo: T. Brady</p>
Ashmeadiella californica female abdomen, photo: T. Brady
<p><em>Ashmeadiella gillettei</em> male face, photo: C. Ritner</p>
Ashmeadiella gillettei male face, photo: C. Ritner
<p><em>Ashmeadiella gillettei </em>male lateral habitus, photo: C. Ritner</p>
Ashmeadiella gillettei male lateral habitus, photo: C. Ritner
<p><em>Ashmeadiella</em> nest, photo: C. Ritner</p>
Ashmeadiella nest, photo: C. Ritner
<p><em>Ashmeadiella</em> nest, photo: C. Ritner</p>
Ashmeadiella nest, photo: C. Ritner