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 apicalapical:
near or at the apex or end of any structure
bands of white hairs 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.).

Diversity

Ashmeadiella contains approximately 60 species (Hurd and Michener 1955Hurd and Michener 1955:
Hurd, P.D. and C.D. Michener. 1955. Megachiline Bees of California (Hymenoptera: Megachilidae). Bulletin of the California Insect Survey (Vol. 3). Berkeley and Los Angeles: University of California Press, 247 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.)

• Arolia present.
• Omaulus omaulus:
  angle between anterior and lateral surfaces of mesepisternum
  carinatecarinate:
  having keels or carinae
  (except subgenus Isosmia).
• Parapsidal line parapsidal line:
  the line that runs submedially along the scutum and corresponds to the median border of the site of origin for flight muscles
  linear and elongate.
• T1 without raised carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  between anterioranterior:
  toward the head or on the head side of a segment being described
  and dorsaldorsal:
  in general, the upper surface
  surfaces.
• Female tarsal claws simple.
• Female T6T6:
  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
  with translucent apicalapical:
  near or at the apex or end of any structure
  lip.
• 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
  and 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
  of subequalsubequal:
  similar but not necessarily exactly equal in size, form, or length
  size, their apicalapical:
  near or at the apex or end of any structure
  margins straight.
• Male T6T6:
  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
  with four apicalapical:
  near or at the apex or end of any structure
  teeth (except the subgenus Isosmia).

May be confused with

Hoplitis and Atoposmia look similar to Ashmeadiella. However, Ashmeadiella differ from these two genera in that 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
and 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
of the males are subequalsubequal:
similar but not necessarily exactly equal in size, form, or length
, whereas 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
and 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
in Hoplitis and Atoposmia are distinctly different in size (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Ashmeadiella (except for the subgenus Isosmia) can also be distinguished by the presence of an omaularomaular:
angle between anterior and lateral surfaces of mesepisternum
carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

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 1939Michener 1939:
Michener, C.D. 1939. A revision of the genus Ashmeadiella (Hymen., Megachilidae). American Midland Naturalist 22: 1ndash;84.). The subgenus Isosmia appears to specialize on Dalea (Yanega 1994Yanega 1994:
Yanega, D. 1994. Nests and hosts of three species of megachild bees (Hymenoptera: Apoidea: Megachilidae) from Coahuila, Meacute;xico. Journal of the Kansas Entomological Society 67: 415ndash;417.).

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 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). In one case, an Ashmeadiella nest was found in the fuel line tubing of a crashed airplane (Rozen and Eickwort 1997Rozen and Eickwort 1997:
Rozen, J. and G. Eickwort. 1997. The entomological evidence. Journal of Forensic Sciences 42: 394ndash;397.). Nest partitions consist of masticated leaf pulp bound with nectar, resin, sap, or gum (Rozen 1987Rozen 1987:
Rozen Jr., J.G., 1987. Nesting biology of the bee Ashmeadiella holtii and its cleptoparasite, a new species of Stelis (Apoidea: Megachilidae). American Museum Novitates 2900: 1ndash;10.). Ashmeadiella rubella lines its nest with flower petals of Dalea spp. (Yanega 1994Yanega 1994:
Yanega, D. 1994. Nests and hosts of three species of megachild bees (Hymenoptera: Apoidea: Megachilidae) from Coahuila, Meacute;xico. Journal of the Kansas Entomological Society 67: 415ndash;417.); 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 1987Rozen 1987:
Rozen Jr., J.G., 1987. Nesting biology of the bee Ashmeadiella holtii and its cleptoparasite, a new species of Stelis (Apoidea: Megachilidae). American Museum Novitates 2900: 1ndash;10.).

Distribution

Ashmeadiella are endemic to North America, ranging from southern Canada to Yucatan, Mexico (Michener 1944Michener 1944:
Michener, C.D. 1944. The distribution of the osmiine bees of the deserts of North America. The American Naturalist 78: 257ndash;266.). 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 1939Michener 1939:
Michener, C.D. 1939. A revision of the genus Ashmeadiella (Hymen., Megachilidae). American Midland Naturalist 22: 1ndash;84.).

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

References

Hurd, P.D. and C.D. Michener. 1955. Megachiline Bees of California (Hymenoptera: Megachilidae). Bulletin of the California Insect Survey (Vol. 3). Berkeley and Los Angeles: University of California Press, 247 pp.

Michener, C.D. 1939. A revision of the genus Ashmeadiella (Hymen., Megachilidae). American Midland Naturalist 22: 1-84.

Michener, C.D. 1944. The distribution of the osmiine bees of the deserts of North America. The American Naturalist 78: 257-266.

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

Rozen Jr., J.G., 1987. Nesting biology of the bee Ashmeadiella holtii and its cleptoparasitecleptoparasite:
bees that lay their eggs in the nest cells of bees in other genera. Their larvae depend on the pollen provided by their host. Since cleptoparasitic bees don't provision their own nests, and instead depend on the pollen collected by their host, the females lack pollen collecting hairs. This often gives them a wasp-like appearance.
, a new species of Stelis (Apoidea: Megachilidae). American Museum Novitates 2900: 1-10.

Rozen, J. and G. Eickwort. 1997. The Entomological Evidence. Journal of Forensic Sciences 42: 394-397.

Yanega, D. 1994. Nests and hosts of three species of megachild bees (Hymenoptera: Apoidea: Megachilidae) from Coahuila, México. Journal of the Kansas Entomological Society 67: 415-417.