Trichothurgus

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Lithurgini
Genus: Trichothurgus Moure, 1949
Subgenera: none
Common name: none

Overview

Trichothurgus are generally robust, black bees that lack hair bands on the abdomen. They often have abundant white or yellow hair on the thorax and first few terga with contrasting black hairs on the legs and apical terga, however, they can also be completely black (Michener 2007; Sarzetti et al. 2012). They range in body length from 7–21 mm.

Diversity

Trichothurgus contains approximately 15 species worldwide; none are known to occur in the U.S. or Canada (Michener 2007).

Diagnostic characteristics

(modified from Michener 2007)

  • First flagellomere 1.5 times as long as broad or longer.
  • Hind tibia with course tubercles that do not end in bristles.
  • Labrum longer than clypeus, often much longer.
  • Lower mandibular tooth longer than median tooth.
  • Maxillary palpus with three segments.
  • Female with anterior, posterior, and outer surfaces of hind tibia uniformly hairy.
  • Female arolia absent.
  • Female tarsal claws simple.
  • Female T6 is hairy and toothed at the posterior margin.
  • Female T6 with a raised, impunctate median ridge.
  • Male arolia present.
  • Male pygidial plate present.

May be confused with

Trichothurgus may be confused with Lithurgus and Microthurge, but Trichothurgus can be differentiated by its large labrum and high density of hairs (Michener 2007).

Known invasives

There are no known invasives.

Host associations

Little is known about the floral associations of Trichothurgus. Trichothurgus bolitophilus visits Amaranthaceae and Asteraceae, while other Trichothurgus, such as T. dubius, have been recorded to visit Cactaceae (Rozen 1973; Sarzetti et al. 2012).

Nesting behavior

Trichothurgus dubius have been found nesting in dead, standing cacti forming a linear series of unlined cells, as well as in vacant nests of wasps in the subfamily Eumeninae (Rozen 1973). Trichothurgus bolitophilus forms unlined nests with clusters of unpartitioned cells in dried horse manure that may be reused by multiple generations (Sarzetti et al. 2012). Multiple eggs may be oviposited per provision (Sarzetti et al. 2012).

Distribution

Trichothurgus is restricted to southeastern South America, and generally occurs in xeric habitats (Michener 2007). It ranges from Peru through northern Chile (Tarapacá) and Argentina (Jujuy), south to the San Jorge Gulf region of Patagonia, Argentina (Michener 2007).

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

<p><em>Trichothurgus dubius</em> female face, photo: C. Ritner</p>
Trichothurgus dubius female face, photo: C. Ritner
<p><em>Trichothurgus dubius</em> female lateral habitus, photo: C. Ritner</p>
Trichothurgus dubius female lateral habitus, photo: C. Ritner
<p><em>Trichothurgus dubius </em>female abdomen, photo: T. Brady</p>
Trichothurgus dubius female abdomen, photo: T. Brady
<p><em>Trichothurgus holomelan </em>male hind tibia, photo: C. Ritner</p>
Trichothurgus holomelan male hind tibia, photo: C. Ritner