Anthidium (Anthidium)

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Anthidium Fabricius, 1804
Subgenus: Anthidium Fabricius, 1804
Common name: none

Overview

Anthidium (s. str.) are black bees, sometimes with sections of brown coloration, with extensive yellow to cream-colored markings (Michener 2007). The maculate abdominal bands are often broken into two or four spots, although sometimes the bands are entire across the terga. They range in body length from 8–19 mm (Michener 2007).

Diagnostic characteristics

(modified from Michener 2007)

  • Pronotal lobe carina can be present or absent.
  • Scutellum is rounded in profile and does not overhang the metanotum and propodeum.
  • Scutellum is not carinate or lamellate.
  • Thorax is parallel sided.
  • T4 is as wide as T1.
  • Female mandible has a strong outer ridge that extends from the upper articulation of the mandible to the middle of the tooth row.
  • Male abdomen apex is curved downwards.
  • Male T7 is developed and usually trifid with a median apical spine as well as a lobe that ranges from slender to broad; however, characteristics of these features can vary by species.

May be confused with

Female Anthidium (s. str.) can be differentiated from the other subgenera within Anthidium based on the combination of a mandible with five or more teeth that are separated by small notches; a labrum with a median longitudinal depression; a lack of juxtantennal carina and arolia; a propodeal triangle base that is slightly punctate, dull, and hairy; T6 with a depressed apical rim and median emargination (Gonzalez and Griswold 2013).

Male Anthidium (s. str.) can be differentiated from the other subgenera within Anthidium based on the combination of T6 with a distinct lateral spine; penis valves divided by a distinct bridge basally; ribbed inner margin ventrally; and lobes apically (Gonzalez and Griswold 2013).

Host associations

The majority of Anthidium (s. str.) are generalists. Anthidium (Anthidium) spp. have been observed visiting Acanthaceae, Adoxaceae, Agavaceae, Aizoaceae, Alliaceae, Amaranthaceae, Apiaceae, Apocynaceae, Asclepiadaceae, Asteraceae, Boraginaceae, Brassicaceae, Cactaceae, Campanulaceae, Caprifoliaceae, Caryophyllaceae, Chenopodiaceae, Cleomaceae, Convolvulaceae, Crassulaceae, Diapensiaceae, Ericaceae, Euphorbiaceae, Fabaceae, Fagaceae, Fumariaceae, Geraniaceae, Grossulariaceae, Iridaceae, Krameriaceae, Lamiaceae, Liliaceae, Loasaceae, Lythraceae, Malvaceae, Nyctaginaceae, Onagraceae, Orobanchaceae, Papaveraceae, Phrymaceae, Plantaginaceae, Polemoniaceae, Polygonaceae, Portulacaceae, Ranunculaceae, Rhamnaceae, Rosaceae, Rubiaceae, Salicaceae, Solanaceae, Tamaricaceae, Themidaceae, Verbenaceae, Violaceae, and Zygophyllaceae (Gonzalez and Griswold 2013).

Nesting behavior

Anthidium (s. str.) species have been observed nesting in the ground in the soil and sand, in preexisting cavities in hollow stems, wood, dead bamboo, beetle burrows, and abandoned ground nests of Anthophora and Diadasia (Davidson 1895; Johnson 1904; Custer and Hicks 1927; Hicks 1929; Grigarick and Stange 1968; Kurtak 1973; Parker 1987; Cane 1996; Payne et al. 2011; Gonzalez and Griswold 2013). Nest plugs and partitions can be comprised of many different materials depending on the species building the nest. These materials include trichomes from a variety of plants, trichomes with pebbles, pebbles, small pieces of woods, masticated plant material, resin, and lizard dung (Davidson 1895; Hicks 1926; Custer and Hicks 1927; Hicks 1929; Ferguson 1962; Jaycox 1966; Jaycox 1967; Krombein 1967; Horning 1969; Müller et al. 1996). Males of A. banningense, A. illustre, A. maculosum, A. manicatum, A. palliventre, A. palmarum, and A. porterae are known to exhibit territorial behaviors by defending boundaries around female’s preferred floral resources (Jaycox 1967; Pechuman 1967; Alcock et al. 1977). Female A. mormonum have been observed aggressively competing over nest space (Hicks 1929).

Diversity

Anthidium (s. str.) consists of more than 160 species worldwide, 92 of which occur in the Western Hemisphere (Gonzalez and Griswold 2013).

Known invasives

Anthidium (s. str.) has two known invasive species in the U.S., A. manicatum and A. oblongatum.

Anthidium manicatum are native to Europe, Asia, and North Africa. Due to their strong ability to colonize populated places, they have since spread to other continents. They were initially introduced to northeastern U.S. from Europe. They now occur in the U.S., Canada, New Zealand, and South America in Peru, Suriname, Paraguay, Argentina, Uruguay, and Brazil. Anthidium manicatum has a high potential to become a globally distributed invasive species (Strange et al. 2011). They are restricted to human-modified habitats (Gonzalez and Griswold 2013).

Anthidium oblongatum occurs throughout most of southern and temperate Europe. They were accidentally introduced to the U.S. in the 1990s (Russo 2016), and have since spread throughout southern Canada and the eastern and midwestern part of the U.S. in Maryland, New York, New Jersey, Pennsylvania, Ohio, Illinois, and Connecticut (Hoebeke and Wheeler 1999; Miller et al. 2002; Romankova 2003; Michener 2007; Maier 2009; Tonietto and Ascher 2009).

Distribution

Anthidium (s. str.) occur on every continent except Australia. They are also absent in the Indo-Malayan tropical region (Michener 2007).


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

<p>Fig 1, <em>Anthidium maculifrons</em> female face, photo: Chelsey Ritner</p>
Fig 1, Anthidium maculifrons female face, photo: Chelsey Ritner
<p>Fig 2, <em>Anthidium maculifrons</em> female lateral habitus, photo: Chelsey Ritner</p>
Fig 2, Anthidium maculifrons female lateral habitus, photo: Chelsey Ritner
<p>Fig 3, <em>Anthidium maculifrons</em> female abdomen, photo: Chelsey Ritner</p>
Fig 3, Anthidium maculifrons female abdomen, photo: Chelsey Ritner
<p>Fig 4, <em>Anthidium maculifrons </em>male face, photo: Chelsey Ritner</p>
Fig 4, Anthidium maculifrons male face, photo: Chelsey Ritner
<p>Fig 5, <em>Anthidium maculifrons </em>male lateral habitus, photo: Chelsey Ritner</p>
Fig 5, Anthidium maculifrons male lateral habitus, photo: Chelsey Ritner
<p>Fig 6, <em>Anthidium maculifrons </em>male abdomen, photo: Chelsey Ritner</p>
Fig 6, Anthidium maculifrons male abdomen, photo: Chelsey Ritner