Microthurge

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Lithurgini
Genus: Microthurge Michener, 1983
Subgenera: none
Common name: none

Overview

Microthurge are slender black bees with pale bands of hair on the terga. They range in body length from 5–8 mm (Michener 2007).

Diversity

Microthurge contains 4 species worldwide (Griswold 1991); none are known to occur in the U.S. or Canada.

Diagnostic characteristics

(modified from Michener 2007)

May be confused with

Microthurge may be confused with Heriades and small Hoplitis due to similar body form and size; however, the males of Heriades and Hoplitis lack a pygidial plate (Michener 2007).

Known invasives

There are no known invasives.

Host associations

Floral associations are unknown.

Nesting behavior

The nesting habits of most species of Microthurge are not known. Female M. corumbae excavate nests in dry rotten wood, forming cells without partitions. They may share common nest entrances; communal nesting reduces parasitism rates because some individuals guard nests while others forage (Garófalo et al. 1992). Nests may be reused by the following generation (Garófalo et al. 1992). Two types of cocoons may be formed by alternating M. corumbae generations. The first annual generation forms thin, single-layered cocoons and exhibits a short diapause (Mello and Garófalo 1986). Alternatively, the second generation forms thick, double-layered cocoons which, presumably, offer greater protection from predators, pathogens, or harsh climactic conditions during the extended diapause period (Mello and Garófalo 1986).

Distribution

Microthurge occurs in South America from Cochabamba, Bolivia east to São Paulo, Brazil and south to Buenos Aires province, Argentina (Michener 2007).

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

<p><em>Microthurge corumbae</em> female face, photo: C. Ritner</p>
Microthurge corumbae female face, photo: C. Ritner
<p><em>Microthurge corumbae</em> female lateral habitus, photo: C. Ritner</p>
Microthurge corumbae female lateral habitus, photo: C. Ritner
<p><em>Microthurge corumbae</em> female abdomen, photo: T. Brady</p>
Microthurge corumbae female abdomen, photo: T. Brady
<p><em>Microthurge pygmaeus</em> female wing, photo: C. Ritner</p>
Microthurge pygmaeus female wing, photo: C. Ritner