Stenomegachile

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Stenomegachile Pasteels, 1965
Common name: none

Overview

Stenomegachile are slender bees with black integumentintegument:
a tough, protective outer layer
and apicalapical:
near or at the apex or end of any structure
bands of white hair 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
. They range in body length from 11–17 mm (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
). This group was recently elevated from a subgenus of Megachile to the status of genus by Gonzalez et al. (2019).

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.
; 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 labrumlabrum:
    part of the head abutting the clypeus, folds down in front of the mouthparts
    is long and parallel-sided.
  • Female mandiblemandible:
    bee teeth, so to speak, usually crossed and folded in front of the mouth
    is long, shiny, and four-toothed.
  • Female hypostomalhypostomal:
    the notched region underneath the head and behind the mandible that holds the folded tongue
    area with a strong tooth posteriorly.
  • Male hypostomalhypostomal:
    the notched region underneath the head and behind the mandible that holds the folded tongue
    area with large tooth behind the mandibularmandibular:
    near the mandible
    base.
  • Male mandiblemandible:
    bee teeth, so to speak, usually crossed and folded in front of the mouth
    four-toothed.
  • Male front tibiatibia:
    the segment of the leg, between the femur and the tarsus
    with longitudinal carinacarina:
    a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
    along the outer margin.
  • 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 long, dense hairs that extend over much of the preapicalpreapical:
    referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
    carinacarina:
    a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
    , which is bilobed.
  • 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
    apicalapical:
    near or at the apex or end of any structure
    margin with laterallateral:
    relating, pertaining, or attached to the side
    teeth.

May be confused with

Stenomegachile may be confused with bees within the genus Maximegachile. Females of both genera have long shiny mandibles and a strong posterior tooth in the hypostomalhypostomal:
the notched region underneath the head and behind the mandible that holds the folded tongue
area, while males of both genera have a bilobed preapicalpreapical:
referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
and laterallateral:
relating, pertaining, or attached to the side
teeth on the apicalapical:
near or at the apex or end of any structure
margin of 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
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
). Female and male Stenomegachile can be differentiated by their four-toothed mandibles. Male Stenomegachile also have long, dense hairs that extend over the preapicalpreapical:
referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
on 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
, which are not present in Maximegachile (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

Floral associations are unknown.

Nesting behavior

Nesting behavior is unknown.

Diversity

Stenomegachile consists of three species (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
; 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.
); none are known to occur in the U.S. or Canada.

Known invasives

There are no known invasives.

Distribution

Stenomegachile are found in Africa, where they range from Eritrea to the Democratic Republic of the Congo, south to Namibia, and also occur in Madagascar (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
; Coetzer and Eardley 2019Coetzer and Eardley 2019:
Coetzer, W. and C. Eardley. 2019. Insights into 260 years of taxonomic research gained from the Catalogue of Afrotropical Bees. African Invertebrates 60: 291-318.
).

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

References

Coetzer, W. and C. Eardley. 2019. Insights into 260 years of taxonomic research gained from the Catalogue of Afrotropical Bees. African Invertebrates 60: 291-318.

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.

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

  Stenomegachile chelostomoides  male face, photo: Chelsey Ritner

Stenomegachile chelostomoides male face, photo: Chelsey Ritner

  Stenomegachile chelistomoides  male lateral habitus, photo: Chelsey Ritner

Stenomegachile chelistomoides male lateral habitus, photo: Chelsey Ritner

  Stenomegachile chelostomoides  male abdomen, photo: Chelsey Ritner

Stenomegachile chelostomoides male abdomen, photo: Chelsey Ritner