Plesianthidium

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Plesianthidium Cameron, 1905
Subgenera: Carinanthidium, Plesianthidium, Spinanthidiellum, Spinanthidium
Common name: none

Overview

Plesianthidium typically have robust bodies which lack any pale markings, except for pale markings and hairs on their face. They range in body length from 7–16 mm, with the largest being P. fulvopilosum, which ranges in body length from 15–16 mm (Michener 2007).

Diversity

Plesianthidium contains 12 species within four subgenera in southern Africa (Michener 2007); none are known to occur in the U.S. or Canada.

Diagnostic characteristics

(modified from Michener 2007)

May be confused with

Plesianthidium, especially species within subgenus Carinanthidium, may be confused with Aspidosmia due to a lack of yellow or pale markings on the abdomen. Plesianthidium males can be distinguished by the presence of a marginal comb on S4 the tridentate T7. Aspidosmia males lack marginal combs on all sterna and have a bilobed or bidentate T7. Females can be readily distinguished because Plesianthidium lacks the scopa-like hairs on the hind tibia present in Aspidosmia.

Known invasives

There are no known invasives.

Host associations

Plesianthidium have been observed visiting flowers within the families Fabaceae, Malvaceae, and Lamiaceae (Gess and Gess 2007).

Nesting behavior

Plesianthidium build nests out of resin (Gess and Gess 2007). Plesianthidium volkmanni has been observed nesting in electrical boxes 1.25 m above the ground (Gess and Gess 2007). Nests include up to seven, separate pot-like cells made of ochre/yellow-colored resin. The females will first create a small saucer to act as a foundation for the nest. The saucer is made out of a different material than the nest (Gess and Gess 2007). Cells are then built horizontally from the base. The nest is plugged using a tapered and narrow spout, which is likely used to ventilate the cells (Gess and Gess 2007).

Distribution

Plesianthidium are distributed in southern Africa, specifically Namibia and South Africa. Almost all species of Plesianthidium are found in Cape Province, South Africa (Michener 2007).

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

<p><em>Plesianthidium calesense</em> female face, photo: C. Ritner</p>
Plesianthidium calesense female face, photo: C. Ritner
<p><em>Plesianthidium calescens</em> female lateral habitus, photo: C. Ritner</p>
Plesianthidium calescens female lateral habitus, photo: C. Ritner
<p><em>Plesianthidium neli</em> female abdomen with brown markings, photo: C. Ritner</p>
Plesianthidium neli female abdomen with brown markings, photo: C. Ritner
<p><em>Plesianthidium hamaguaensis</em> male T6 with tridentate apical margin, photo: C. Ritner</p>
Plesianthidium hamaguaensis male T6 with tridentate apical margin, photo: C. Ritner
<p><em>Plesianthidium</em> sp. male terga, photo: C. Ritner</p>
Plesianthidium sp. male terga, photo: C. Ritner