Megachile (Chrysosarus)

Taxonomy

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

Overview

Megachile (Chrysosarus) have black integument and can have reddish, tan, gray, or yellow hairs that often form apical bands on their terga (Michener 2007). They range in body length from 8–17 mm (Michener 2007).

Diagnostic characteristics

(modified from Michener 2007; Gonzalez 2008; Praz 2017)

  • Female mandible is five-toothed.
  • Female mandibular teeth completely lack cutting edges between them.
  • Female sterna with incomplete apical hair bands.
  • Female T6 straight in profile.
  • Male fore coxa has a short spine, occasionally a few short, red bristles at the base.
  • Male mandible is three-toothed and sometimes has a small inferior projection.
  • Male front tarsi are enlarged and pale.
  • Male T6 preapical carina has a median apical emargination.

May be confused with

Male Megachile (Chrysosarus) may be confused with bees in the subgenus Megachile (Zonomegachile) since they both have three-toothed mandibles, enlarged front tarsi, a spine on the fore coxa, and the T6 has a preapical carina with a strong median emargination (Michener 2007). Male M. (Chrysosarus), however, lack the strong hypostomal projection at the mandibular base that is present in M. (Zonomegachile). Female Megachile (Chrysosarus) can be differentiated from Megachile (Zonomegachile) by the lack of cutting edges on the mandible (Michener 2007).

Host associations

Megachile (Chrysosarus) have been observed visiting the flowers of Asteraceae, Convolvulaceae, Fabaceae, Hydrophyllaceae, Lamiaceae, Lythraceae, Malvaceae, Onagraceae, Oxalidaceae, Passifloraceae, Ranunculaceae, Rubiaceae, Solanaceae, Verbenaceae, and Zygophyllaceae (Raw 2006; Raw 2007).

Nesting behavior

Megachile (Chrysosarus) nests are constructed out of chewed leaves in pre-existing cavities (Laroca 1971; Laroca et al. 1992; Zillikens and Steiner 2004). Brood cells differ from other Megachile subgenera in that they contain a layer of mud between layers of petals and leaves (Laroca et al. 1992; Raw 2007). Megachile (Chrysosarus) have been observed nesting in bamboo, bramble, wood, galls, trap nests, bromeliad leaves, the abandoned nests of digger bees (Centris) and potter wasps (Eumenidae), and in cane roofs of houses (Raw 2007).

Diversity

Megachile (Chrysosarus) consists of fifty-six species (Raw 2007); none are known to occur in the U.S. or Canada.

Known invasives

There are no known invasives.

Distribution

Megachile (Chrysosarus) occurs predominantly in South America where they are found in Guyana, Peru, Brazil, Paraguay, Argentina, and Panama (Raw 2007).

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

<p><em>Megachile vestis </em>female face, photo: Shaun Heller</p>
Megachile vestis female face, photo: Shaun Heller
<p><em>Megachile vestis </em>female lateral habitus, photo: Shaun Heller</p>
Megachile vestis female lateral habitus, photo: Shaun Heller
<p><em>Megachile vestis </em>female abdomen, photo: Shaun Heller</p>
Megachile vestis female abdomen, photo: Shaun Heller
<p><em>Megachile vestis </em>male face, photo: Brooke Bagot</p>
Megachile vestis male face, photo: Brooke Bagot
<p><em>Megachile vestis </em>male lateral habitus, photo: Shaun Heller</p>
Megachile vestis male lateral habitus, photo: Shaun Heller
<p><em>Megachile vestis </em>male abdomen, photo: Shaun Heller</p>
Megachile vestis male abdomen, photo: Shaun Heller
<p><em>Megachile albopunctata</em> female abdomen, photo: Joshua Hengel</p>
Megachile albopunctata female abdomen, photo: Joshua Hengel