Austrostelis

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Austrostelis Michener and Griswold, 1994
Subgenera: none
Common name: none

Overview

Austrostelis are slender and black bees that range in body length from 5.5–8.5 mm. They can have integumentintegument:
a tough, protective outer layer
with variable amounts of pale yellow to orange maculations on the head, thorax, and abdomen, or can be almost entirely yellow (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Austrostelis are cleptoparasites, so they lack 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
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Diversity

Austrostelis contains 9 species worldwide; none are known to occur in the U.S. or Canada (Urban and Moore 2012).

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.)

• Arolia present.
• Juxtantennal carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  present.
• Middle tibiatibia:
  the segment of the leg, between the femur and the tarsus
  with one apicalapical:
  near or at the apex or end of any structure
  spine.
• Propodeum propodeum:
  the last segment of the thorax
  basalbasal:
  originating at the foundation of a structure
  area with strong pits and posterior carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  .
• T1 lacks carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  where the dorsaldorsal:
  in general, the upper surface
  and anterioranterior:
  toward the head or on the head side of a segment being described
  surfaces meet.
• Female hind tibiatibia:
  the segment of the leg, between the femur and the tarsus
  apexapex:
  end of any structure
  bearing a distinct flat projection.
• 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
  absent.
• Female tarsal claws bifidbifid:
  divided into two branches; forked
  .
• Female T5T5:
  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 laterallateral:
  relating, pertaining, or attached to the side
  teeth.
• Male S4S4:
  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
  without laterallateral:
  relating, pertaining, or attached to the side
  teeth.
• Male S5S5:
  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
  and S6S6:
  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
  with laterallateral:
  relating, pertaining, or attached to the side
  teeth.

May be confused with

Austrostelis may be confused with Hypanthidioides because they are superficially similar in color and body conformation. However, females Hypanthidioides lack the characteristic projection of the hind tibiatibia:
the segment of the leg, between the femur and the tarsus
of Austrostelis and have scopae (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Hoplostelis is also similar; however, females also lack the flat projection on the hind tibiatibia:
the segment of the leg, between the femur and the tarsus
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Known invasives

There are no known invasives.

Host associations

Austrostelis are cleptoparasiticcleptoparasitic:
bees that lay their eggs in the nest cells of bees in other genera. Their larvae depend on the pollen provided by their host. Since cleptoparasitic bees don't provision their own nests, and instead depend on the pollen collected by their host, the females lack pollen collecting hairs. This often gives them a wasp-like appearance.
, hence they do not gather pollen. Presumably, they utilize a wide variety of floral nectar resources. The host range of Austrostelis is largely unknown; however, they have been found in the nests of other Anthidiini (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Austrostelis catamarcencis has been recorded from Epanthidium tigrinum as a host in Brazil; A. iheringi has been reared from an unidentified anthidiine nest (Zanella and Ferreira 2005Zanella and Ferreira 2005:
Zanella, F.C.V. and A.G. Ferreira. 2005. Registro de hospedeiro de Austrostelis Michener amp; Griswold (Hymenoptera: Megachilidae) e de sua ocorrecirc;ncia na Caatinga. Neotropical Entomology 34: 857ndash;858.).

Nesting behavior

Austrostelis is cleptoparasiticcleptoparasitic:
bees that lay their eggs in the nest cells of bees in other genera. Their larvae depend on the pollen provided by their host. Since cleptoparasitic bees don't provision their own nests, and instead depend on the pollen collected by their host, the females lack pollen collecting hairs. This often gives them a wasp-like appearance.
on pollen provisions found in the nests of other bees. This behavior is likely restricted to NeotropicalNeotropical:
biogeographic region that includes South and Central America, the Caribbean Islands, southern Florida, and the southern Mexican lowlands
Anthidiini (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Austrostelis iheringi has been observed parasitizing host species in bamboo stalks (Cordeiro et al. 2015Cordeiro et al. 2015:
Cordeiro, G.D., A.L.O. Nascimento, I. Alves-dos-Santos, and C.A. Garoacute;falo. 2015. The cleptoparasitic bee Austrostelis iheringi (Schrottky, 1910) (Anthidiini, Megachilidae): new geographical records and potential hosts. Journal of the Kansas Entomological Society 88: 453ndash;456.). The host female built a continuous, linear nest out of resin within the bamboo cane. Austrostelis iheringi occupied the entire nest with its diagonally constructed cocoon and feces (Cordeiro et al. 2015Cordeiro et al. 2015:
Cordeiro, G.D., A.L.O. Nascimento, I. Alves-dos-Santos, and C.A. Garoacute;falo. 2015. The cleptoparasitic bee Austrostelis iheringi (Schrottky, 1910) (Anthidiini, Megachilidae): new geographical records and potential hosts. Journal of the Kansas Entomological Society 88: 453ndash;456.).

Distribution

Austrostelis is a New WorldNew World:
the Western Hemisphere; especially the continental landmass of North and South America
genus ranging from Mexico south to Colombia, Brazil, and Argentina (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

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

References

Cordeiro, G.D., A.L.O. Nascimento, I. Alves-dos-Santos, and C.A. Garófalo. 2015. The cleptoparasitic:

bee Austrostelis iheringi (Schrottky, 1910) (Anthidiini, Megachilidae): new geographical records and potential hosts. Journal of the Kansas Entomological Society 88: 453-456.

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

Urban, D. and J. Moure. 2012. Anthidiini Ashmead, 1899. In Moure, J. S., Urban, D., and Melo, G. A. R. (Orgs.). Catalogue of Bees (Hymenoptera, Apoidea) in the NeotropicalNeotropical:
biogeographic region that includes South and Central America, the Caribbean Islands, southern Florida, and the southern Mexican lowlands
Region. 

Zanella, F.C.V. and A.G. Ferreira. 2005. Registro de hospedeiro de Austrostelis Michener & Griswold (Hymenoptera: Megachilidae) e de sua ocorrência na Caatinga. NeotropicalNeotropical:
biogeographic region that includes South and Central America, the Caribbean Islands, southern Florida, and the southern Mexican lowlands
Entomology 34: 857-858.