Megachile (Melanosarus)

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Megachile Latreille, 1802
Subgenus: Melanosarus Mitchell, 1934
Common name: none

Overview

Megachile (Melanosarus) are almost entirely black bees with black integumentintegument:
a tough, protective outer layer
and all or largely black hairs (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Gonzalez 2008Gonzalez 2008:
Gonzalez, V.H. 2008. Phylogeny and classification of the bee tribe Megachilini (Hymenoptera: Apoidea: Megachilidae), with emphasis on the genus Megachile. Thesis: Department of Ecology and Evolutionary Biology and the College of Liberal Arts and Science of the University of Kansas: 1-274.). They range in body length from 10–16 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 Mitchell 1937aMitchell 1937a:
Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic region. Part VI. Taxonomy of the subgenera Argyropile, Leptorachis, Pseudocentron, Acentron, and Melanosarus. Transactions of the American Entomological Society 63: 45-83.; Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Gonzalez 2008Gonzalez 2008:
Gonzalez, V.H. 2008. Phylogeny and classification of the bee tribe Megachilini (Hymenoptera: Apoidea: Megachilidae), with emphasis on the genus Megachile. Thesis: Department of Ecology and Evolutionary Biology and the College of Liberal Arts and Science of the University of Kansas: 1-274.)

• Scutum scutum:
  the large segment on top of the thorax located between the wings and behind the head
  is less densely punctatepunctate:
  studded with tiny holes
  than most Megachile subgenera; often punctures are separated by at least one puncture width.
• Female hypostomalhypostomal:
  the notched region underneath the head and behind the mandible that holds the folded tongue
  area has a depressed, smooth, shiny area that is enclosed by a short transverse carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  .
• Female mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  is five-toothed with a long cutting edge in the second interspace and no cutting edge in the third interspace.
• Female 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
  has a reduced scopascopa:
  modified hairs for carrying pollen; often branched and dense hairs on the hind-leg, or on the ventral surface of the abdomen in Megachilidae
  and is mostly bare on the apicalapical:
  near or at the apex or end of any structure
  half.
• Male front tarsitarsi:
  the group of segments at the end of the leg following the tibia
  are distinctly expanded and pale.
• Male mid-tibial spurs are absent.

May be confused with

Male Megachile (Melanosarus) may be confused with bees within the subgenus Megachile (Pseudocentron) because females in both subgenera have reduced scopal hairs on 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
and males in both lack a mid-tibial spur. However, Megachile (Pseudocentron) males have an immovable prong or tooth on the mid-tibia that is absent in Megachile (Melanosarus) (Mitchell 1937aMitchell 1937a:
Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic region. Part VI. Taxonomy of the subgenera Argyropile, Leptorachis, Pseudocentron, Acentron, and Melanosarus. Transactions of the American Entomological Society 63: 45-83.; Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Female Megachile (Melanosarus) can be differentiated from Megachile (Pseudocentron) by their mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
, which is five-toothed and has a long cutting edge in the second interspace (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Host associations

Megachile (Melanosarus) have been observed visiting flowers of plants in the families Anacardiaceae, Aquifoliaceae, Arecaceae, Asteraceae, Haemodoraceae, Onagraceae and Smilacaceae (Deyrup et al. 2002Deyrup et al. 2002:
Deyrup, M., Edirisinghe, J. and Norden, B. 2002. The diversity and floral hosts of bees at the Archbold Biological Station, Florida (Hymenoptera: Apoidea). Insecta Mundi 16: 87-120, 544.; Hall and Ascher 2010Hall and Ascher 2010:
Hall, H.G. and J.S. Ascher. 2010. Surveys of bees (Hymenoptera: Apoidea: Anthophila) in natural areas of Alachua County in north-central Florida. Florida Entomologist 93(4): 609-629.).

Nesting behavior

Megachile (Melanosarus) nests in pre-existing cavities, including in bamboo and cardboard trap nests (Eickwort et al. 1981Eickwort et al. 1981:
Eickwort, G.C., R.W. Matthews, and J. Carpenter. 1981. Observations on the nesting behavior of Megachile rubi and M. texana with a discussion of the significance of soil nesting in the evolution of megachilid bees (Hymenoptera: Megachilidae). Journal of the Kansas Entomological Society. 54: 557-570.; Marques and Gaglianone 2013Marques and Gaglianone 2013:
Marques, M.F. and M.C. Gaglianone. 2013. Nesting biology and altitudinal variation in the abundance of Megachile (Melanosarus) nigripennis Spinolla (Hymenoptera, Megachilidae) in an inselberg in the Mata Atlacirc;ntica, Rio de Janeiro. Bioscience Journal 29(1): 198-208.). They have been observed constructing their nests from pieces of cut leaves (Marques and Gaglianone 2013Marques and Gaglianone 2013:
Marques, M.F. and M.C. Gaglianone. 2013. Nesting biology and altitudinal variation in the abundance of Megachile (Melanosarus) nigripennis Spinolla (Hymenoptera, Megachilidae) in an inselberg in the Mata Atlacirc;ntica, Rio de Janeiro. Bioscience Journal 29(1): 198-208.).

Diversity

Megachile (Melanosarus) is a subgenus of eight species, two of which occur in 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.).

Known invasives

There are no known invasives.

Distribution

Megachile (Melanosarus) are distributed across North and South America. They are found from the state of Maryland, U.S., to Argentina in South America (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

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References

Deyrup, M., J. Edirisinghe, and B. Norden. 2002. The diversity and floral hosts of bees at the Archbold Biological Station, Florida (Hymenoptera: Apoidea). Insecta Mundi: 16: 87-120.

Eickwort, G.C., R.W. Matthews, and J. Carpenter. 1981. Observations on the nesting behavior of Megachile rubi and M. texana with a discussion of the significance of soil nesting in the evolution of Megachilid bees (Hymenoptera: Megachilidae). Journal of the Kansas Entomological Society 54: 557-570.

Gonzalez, V.H. 2008. Phylogeny and classification of the bee tribe Megachilini (Hymenoptera: Apoidea: Megachilidae), with emphasis on the genus Megachile. Thesis: Department of Ecology and Evolutionary Biology and the College of Liberal Arts and Science of the University of Kansas: 1-274.

Hall, H.G. and J.S. Ascher. 2010. Surveys of bees (Hymenoptera: Apoidea: Anthophila) in natural areas of Alachua County in north-central Florida. Florida Entomologist 93(4): 609-629.

Marques, M.F. and M.C. Gaglianone. 2013. Nesting biology and altitudinal variation in the abundance of Megachile (Melanosarus) nigripennis Spinolla (Hymenoptera, Megachilidae) in an inselberg in the Mata Atlântica, Rio de Janeiro. Bioscience Journal 29(1): 198-208.

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

Mitchell, T.B. 1937. A revision of the genus Megachile in the NearcticNearctic:
biogeographical region comprising North America as far south as northern Mexico, together with Greenland
region. Part VI. Taxonomy of the subgenera Argyropile, Leptorachis, Pseudocentron, Acentron, and Melanosarus. Transactions of the American Entomological Society 63: 45-83.