Megachile (Pseudocentron)

Taxonomy

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

Overview

Megachile (Pseudocentron) have primarily black integumentintegument:
a tough, protective outer layer
and often have gray, tan, white, reddish, or black hair (Durante et al. 2014Durante et al. 2014:
Durante, S., J.P. Torretta, and M.G. Colombo. 2014. Descriptions of unknown sexes, new geographical records, and host associations for two South American species of Megachile (Hymenoptera: Megachilidae). Zootaxa 3814(1): 133-138.). They range in body length from 8–16 mm (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Megachile (Pseudocentron) is the largest subgenus of Megachile in Central and 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.; 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.; Torretta et al. 2012Torretta et al. 2012:
Torretta, J.P., S.P. Durante, M.G. Colombo, and A.M. Basilio. 2012. Nesting biology of the leafcutting bee Megachile ( Pseudocentron ) gomphrenoides (Hymenoptera: Megachilidae) in an agro-ecosystem. Apidologie 43: 624-633.).

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.; Gonzalez et al. 2019Gonzalez et al. 2019:
Gonzalez, V.H., G.T. Gustafson, and M.S. Engel. 2019. Morphological phylogeny of Megachilini and the evolution of leaf-cutter behavior in bees (Hymenoptera: Megachilidae). Journal of Melittology (85): 1-123.)

• Female clypeusclypeus:
  a section of the face below the antennae, demarcated by the epistomal sutures
  apicalapical:
  near or at the apex or end of any structure
  margin is straight.
• Female hypostomalhypostomal:
  the notched region underneath the head and behind the mandible that holds the folded tongue
  area is depressed, smooth, shiny, and enclosed laterally 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
  with inner tooth acute or rounded.
• Female mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  is four-toothed with a complete and long cutting edge in the third interspace, an incomplete cutting edge in the second interspace, and a rounded or acute inner tooth.
• 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
  apicalapical:
  near or at the apex or end of any structure
  margin is broadly truncatetruncate:
  ending abruptly, or squared off
  or rounded.
• 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
  posterior half is bare except for a row of short subapicalsubapical:
  located just behind the apex of the segment or body part
  hairs.
• Male mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  with basalbasal:
  originating at the foundation of a structure
  inferior process or projection.
• Male hypostomalhypostomal:
  the notched region underneath the head and behind the mandible that holds the folded tongue
  area deeply excavated.
• Male front coxacoxa:
  the basal segment of the leg
  with long spine.
• Male front tibiatibia:
  the segment of the leg, between the femur and the tarsus
  distinctly expanded.
• Male front tarsustarsus:
  the group of segments at the end of the leg following the tibia
  is slender and usually black.
• Male middle tibiatibia:
  the segment of the leg, between the femur and the tarsus
  has a spur-like apicalapical:
  near or at the apex or end of any structure
  prong or large, acute tooth.

May be confused with

Megachile (Pseudocentron) may be confused with bees in the subgenera Megachile (Acentron) and Megachile (Leptorachis) because the posterior half of 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
is bare except for a row of short, subapicalsubapical:
located just behind the apex of the segment or body part
hairs (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.). Megachile (Pseudocentron) can be differentiated from the other two subgenera by the male’s mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
with basalbasal:
originating at the foundation of a structure
inferior projection, large front spines on the coxacoxa:
the basal segment of the leg
, and expanded front legs (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.). Megachile (Pseudocentron) can also be differentiated from Megachile (Leptorachis) by the large, incomplete cutting edge in the second interspace of the female mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Megachile (Peudocentron) may also be confused with Megachile (Argyropile) because of the dorsally bent apicalapical:
near or at the apex or end of any structure
rim 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
. However, Megachile (Pseudocentron) usually has a thinner and more translucent apicalapical:
near or at the apex or end of any structure
rim (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.).

Host associations

The following plant families have been identified as floral resources for Megachile (Pseudocentron) through flower-visiting observations and pollen analysis of nest provisions: Anacardiaceae, Apocynaceae, Arecaceae, Asteraceae, Brassicaceae, Combretaceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Goodeniaceae, Lamiaceae, Malvaceae, Onagraceae, Passifloraceae, Phyllanthaceae, Pontederiaceae, Rubiaceae, Solanaceae, Surianaceae, Tiliaceae, and Verbenaceae (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.; Albuquerque et al. 2007Albuquerque et al. 2007:
Albuquerque, P.M.C.D., J.M.F.D. Camargo, and J.Acirc;.C. Mendonccedil;a. 2007. Bee community of a beach dune ecosystem on Maranhatilde;o Island, Brazil. Brazilian Archives of Biology and Technology 50(6): 1005-1018.; Landry et al. 2014Landry et al. 2014:
Landry, C.L., N.B. Elliott, and M.R. Vitale. 2014. Nesting ecology of Megachile ( Pseudocentron ) alleni Mitchell (Hymenoptera: Megachilidae) on San Salvador Island, the Bahamas. Journal of the Kansas Entomological Society 87: 37-46.; Marinho et al. 2018Marinho et al. 2018:
Marinho, D., D.B. Muniz, and G.G. Azevedo. 2018. Nesting biology of three Megachile (Hymenoptera: Megachilidae) species from Eastern Amazonia, Brazil. Revista Brasileira de Entomologia 62(2): 97-106.).

Nesting behavior

Megachile (Pseudocentron) are cavity-nesters which have been recorded nesting in trap nests, under rocks, and under asphalt debris along roads (Torretta et al. 2012Torretta et al. 2012:
Torretta, J.P., S.P. Durante, M.G. Colombo, and A.M. Basilio. 2012. Nesting biology of the leafcutting bee Megachile ( Pseudocentron ) gomphrenoides (Hymenoptera: Megachilidae) in an agro-ecosystem. Apidologie 43: 624-633.; Landry et al. 2014Landry et al. 2014:
Landry, C.L., N.B. Elliott, and M.R. Vitale. 2014. Nesting ecology of Megachile ( Pseudocentron ) alleni Mitchell (Hymenoptera: Megachilidae) on San Salvador Island, the Bahamas. Journal of the Kansas Entomological Society 87: 37-46.). These bees build nests using leaflets and cut leaf pieces, which they often cut into specific rectangular to oblong shapes (Marinho et al. 2018Marinho et al. 2018:
Marinho, D., D.B. Muniz, and G.G. Azevedo. 2018. Nesting biology of three Megachile (Hymenoptera: Megachilidae) species from Eastern Amazonia, Brazil. Revista Brasileira de Entomologia 62(2): 97-106.).

Diversity

Megachile (Pseudocentron) consists of approximately 66 species (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Ascher and Pickering 2011Ascher and Pickering 2011:
Ascher, J. and J. Pickering. 2011. Bee species guide (Hymenoptera: Apoidea: Anthophila). http://www.discoverlife.org/mp/20q?guide=Apoidea_species .).

Known invasives

There are no known invasives.

Distribution

Megachile (Pseudocentron) are native to North and South America. They occur from the southern U.S. (southern California to North Carolina) south through South America to Chile and Argentina.

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

References

Ascher, J. and J. Pickering. 2011. Bee species guide (Hymenoptera: Apoidea: Anthophila). http://www.discoverlife.org/mp/20q?guide=Apoidea_species.

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.

Durante, S., J.P. Torretta, and M.G. Colombo. 2014. Descriptions of unknown sexes, new geographical records, and host associations for two South American species of Megachile (Hymenoptera: Megachilidae). Zootaxa 3814(1): 133-138.

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.

Gonzalez, V.H., G.T. Gustafson, and M.S. Engel. 2019. Morphological phylogeny of Megachilini and the evolution of leaf-cutter behavior in bees (Hymenoptera: Megachilidae). Journal of Melittology (85): 1-123.

Landry, C.L., N.B. Elliott, and M.R. Vitale. 2014. Nesting ecology of Megachile (Pseudocentron) alleni Mitchell (Hymenoptera: Megachilidae) on San Salvador Island, the Bahamas. Journal of the Kansas Entomological Society 87: 37-46.

Marinho, D., D.B. Muniz, and G.G. Azevedo. 2018. Nesting biology of three Megachile (Hymenoptera: Megachilidae) species from Eastern Amazonia, Brazil. Revista Brasileira de entomologia 62(2): 97-106.

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.

Torretta, J.P., S.P. Durante, M.G. Colombo, and A.M. Basilio. 2012. Nesting biology of the leafcutting bee Megachile (Pseudocentron) gomphrenoides (Hymenoptera: Megachilidae) in an agro-ecosystem. Apidologie 43: 624-633.