Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Gronoceras Cockerell, 1907
Subgenera: none
Common name: none


Gronoceras are large, elongate bees ranging in body length from 17–29 mm (Michener 2007). They often have black integument with grey and black pubescence in addition to large areas of red or reddish-yellow pubescence on their thorax and head (Michener 2007). Gronoceras was previously a subgenus of Megachile (Trunz et al. 2016).


Gronoceras contains 10 species (Michener 2007); none are known to occur in the U.S. or Canada (Michener 2007).

Diagnostic characteristics

(modified from Michener 2007 unless otherwise stated)

May be confused with

Gronoceras may be confused with species in the subgenus Megachile (Stenomegachile) due to similar dense hairs on the male T6. Gronoceras can be differentiated by the presence of three apical spines on the front and middle tibia (Michener 2007).

Known invasives

There was a single record of Gronoceras in Jamaica that indicates it may have been introduced to the area, but there is no evidence that the genus established there (Michener 2007).

Host associations

Gronoceras have been observed pollinating Ansellia africana, Cajanus cajan, and Vanilla imperialis (FAOUNR 2008; Martin 2009).

Nesting behavior

Similar to many subgenera of Megachile, Gronoceras build nests using resin (Litman 2012). Gronoceras has been observed nesting in earthen walls and wooden posts (FAOUNR 2008).


Gronoceras occurs throughout Africa, from Senegal to Eritrea, south to Namibia, and Natal in South Africa (Michener 2007).

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

<p><em>Gronoceras africanibia</em> female face, photo: C. Ritner</p>
Gronoceras africanibia female face, photo: C. Ritner
<p><em>Gronoceras africanibia </em>female lateral habitus, photo: C. Ritner</p>
Gronoceras africanibia female lateral habitus, photo: C. Ritner
<p><em>Gronoceras africanibia</em> female abdomen, photo: C. Ritner</p>
Gronoceras africanibia female abdomen, photo: C. Ritner
<p><em>Gronoceras felina</em> female middle tibia with three apical spines, photo: C. Ritner</p>
Gronoceras felina female middle tibia with three apical spines, photo: C. Ritner