Megachile (Dasymegachile)

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Megachile Latreille, 1802
Subgenus: Dasymegachile Mitchell, 1943
Common name: none

Overview

Megachile (Dasymegachile) is a subgenus of robust bees with black integumentintegument:
a tough, protective outer layer
that is usually covered in long, dense hair that does not form apicalapical:
near or at the apex or end of any structure
bands of hair on the 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
. Females have entirely black 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
(Durante et al. 2006Durante et al. 2006:
Durante, S., A.H. Abrahamovich, and M. Lucia. 2006. El subgeacute;nero Megachile ( Dasymegachile ) Mitchell con especial referencia a las especies Argentinas (Hymenoptera: Megachilidae). Neotropical Entomology 35: 791-802.; Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). They range in body length from 10–15 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 Durante et al. 2006Durante et al. 2006:
Durante, S., A.H. Abrahamovich, and M. Lucia. 2006. El subgeacute;nero Megachile ( Dasymegachile ) Mitchell con especial referencia a las especies Argentinas (Hymenoptera: Megachilidae). Neotropical Entomology 35: 791-802.; 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.)

• Female mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  four-toothed, with an incomplete cutting edge in the second interspace and a complete cutting edge in the third interspace.
• Female mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  with upper tooth acute or right-angled.
• Female 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
  black, without apicalapical:
  near or at the apex or end of any structure
  bands of hair on the sternasterna:
  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
  beneath.
• Male antennal segments F1 and F2 are nearly equal in length.
• Male front coxacoxa:
  the basal segment of the leg
  without a spine.
• Male mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  three-toothed, although the middle tooth is sometime notched which can cause it to appear four-toothed.
• Male mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  without an inferior projection.

May be confused with

Megachile (Dasymegachile) and Megachile (Cressoniella) are similarly sized and both have four-toothed mandibles with cutting edges in the second and third interspaces (Raw 2007Raw 2007:
Raw, A. 2007. An annotated catalogue of the leafcutter and mason bees (genus Megachile ) of the Neotropics. Zootaxa 1601: 1-127.; 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.). However, female Megachile (Dasymegachile) have mandibles with an acute or right-angular upper tooth, whereas Megachile (Cressoniella) have an upper tooth which is rounded, truncatetruncate:
ending abruptly, or squared off
, or incised (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Male Megachile (Dasymegachile) antennal segments F1 and F2 are about the same length and mandibles are three-toothed (occasionally the middle tooth is notched). In contrast Megachile (Cressoniella) have an F1 that is shorter than F2, and a four-toothed mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
(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

Through both observation records and pollen analysis, a number of plant families have been recorded as floral resources of Megachile (Dasymegachile), including Alstroemeriaceae, Apiaceae, Asteraceae, Aizoaceae, Boraginaceae, Cactaceae, Fabaceae, Lamiaceae, Loasaceae, Onagrariaceae, Resedaceae, and Scrophulariaceae (Durante et al. 2006Durante et al. 2006:
Durante, S., A.H. Abrahamovich, and M. Lucia. 2006. El subgeacute;nero Megachile ( Dasymegachile ) Mitchell con especial referencia a las especies Argentinas (Hymenoptera: Megachilidae). Neotropical Entomology 35: 791-802.).

Nesting behavior

Bees in Megachile (Dasymegachile) build nests from cut leaves or petals in existing cavities (Montalva et al. 2012Montalva et al. 2012:
Montalva, J., B. Castro, and J.L. Allendes. 2012. Nesting biology of Megachile semirufa (Hymenoptera: Megachilidae: Dasymegachile) in high mountain, Chile. Caldasia 34(2): 475-481.). Nesting location preferences vary by species. Megachile semirufa, a high-altitude species, builds nests under flat rocks in the Andes Mountains (Montalva et al. 2012Montalva et al. 2012:
Montalva, J., B. Castro, and J.L. Allendes. 2012. Nesting biology of Megachile semirufa (Hymenoptera: Megachilidae: Dasymegachile) in high mountain, Chile. Caldasia 34(2): 475-481.). Megachile joergenseni nests in plant material and has been observed nesting in galls (of Duvana dependens), bamboo, and in the canes used for thatched roofs (Montalva et al. 2012Montalva et al. 2012:
Montalva, J., B. Castro, and J.L. Allendes. 2012. Nesting biology of Megachile semirufa (Hymenoptera: Megachilidae: Dasymegachile) in high mountain, Chile. Caldasia 34(2): 475-481.; Raw 2007Raw 2007:
Raw, A. 2007. An annotated catalogue of the leafcutter and mason bees (genus Megachile ) of the Neotropics. Zootaxa 1601: 1-127.). Megachile saulcyi nests in cavities in walls or soil and will also reuse old nests made by potter wasps (Eumeninae) and thread-waisted wasps (Sphecidae) (Montalva et al. 2012Montalva et al. 2012:
Montalva, J., B. Castro, and J.L. Allendes. 2012. Nesting biology of Megachile semirufa (Hymenoptera: Megachilidae: Dasymegachile) in high mountain, Chile. Caldasia 34(2): 475-481.; Raw 2007Raw 2007:
Raw, A. 2007. An annotated catalogue of the leafcutter and mason bees (genus Megachile ) of the Neotropics. Zootaxa 1601: 1-127.).

Diversity

Megachile (Dasymegachile) consists of fifteen species (Ascher and Pickering 2020Ascher and Pickering 2020:
Ascher, J.S. and J. Pickering. 2020. Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila). https://www.discoverlife.org/mp/20p?see=Carinulaamp;name=Megachileamp;flags=subgenus :); none are known to occur in the U.S. or Canada.

Known invasives

There are no known invasives. 

Distribution

Megachile (Dasymegachile) is a South American subgenus most commonly found at high altitudes in the Andes mountain range. Their range extends from southern Argentina and Chile northward to Peru and Brazil (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Raw 2007Raw 2007:
Raw, A. 2007. An annotated catalogue of the leafcutter and mason bees (genus Megachile ) of the Neotropics. Zootaxa 1601: 1-127.; 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.).

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

References

Ascher, J.S. and J. Pickering. 2020. Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila). https://www.discoverlife.org/mp/20p?see=Dasymegachile&name=Megachile&flags=subgenus:

Durante, S., A.H. Abrahamovich, and M. Lucia. 2006. El subgénero Megachile (Dasymegachile) Mitchell con especial referencia a las especies Argentinas (Hymenoptera: Megachilidae). NeotropicalNeotropical:
biogeographic region that includes South and Central America, the Caribbean Islands, southern Florida, and the southern Mexican lowlands
Entomology 35: 791-802.

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.

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

Montalva, J., B. Castro, and J.L. Allendes. 2012. Nesting biology of Megachile semirufa (Hymenoptera: Megachilidae: Dasymegachile) in high mountain, Chile. Caldasia 34(2): 475-481.

Raw, A. 2007. An annotated catalogue of the leafcutter and mason bees (genus Megachile) of the Neotropics. Zootaxa 1601: 1-127.