Anthidium edwardsii

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Anthidium Fabricius, 1804
Subgenus: A. (Anthidium) Fabricius, 1804
Species: Anthidium edwardsii Cresson, 1878
Common name: none

Overview

Anthidium (Anthidium) edwardsii are primarily black with yellow maculations and have dark brown antennae, legs, and abdomen (Gonzalez and Griswold 2013). Females have white pubescence, except for yellow or brown hairs on the clypeus, vertex, inner surface of the tarsi, T1T5 depressed marginal zones, and S6. Females have a body length of 8.5–10.9 mm, and males range in length from 11.5–13.1 mm (Gonzalez and Griswold 2013).

Diagnostic characteristics

(modified from Gonzalez and Griswold 2013)

  • Female labrum has large preapical projections that curve upwards, and lacks basal protuberances.
  • Female mandible has five teeth.
  • Female propodeal triangle is dull and finely lineolate.
  • Female hind tibia without anterior carina.
  • Female T1T5 discal areas are weakly elevated with course, dense punctures.
  • Female T1T5 discal margins are narrow, smooth, and shiny.
  • Female T6 lacks a lateral angle, and is slightly swollen preapically with a depressed, narrow apical rim.
  • Female T6 preapical carina is crenulate.
  • Male labrum with preapical projections that are larger than those in females.
  • Male S4 with broad median apical brush of short, dense, reddish-brown hairs.
  • Male S4 apical margin is slightly concave medially.
  • Male S6 has small lateral spines and a rectangular median lobe.
  • Male S8 has a long, narrow apical process that is apically bifid.
  • Male T6 lateral spine is straight, and as long as the T7 median spine.
  • Male T7 lateral lobe tapers apically, and the apex appears subtriangular.

May be confused with

Female Anthidium edwardsii may be confused with A. placitum due to their similar size and the shape of the clypeus (Gonzalez and Griswold 2013). However, A. edwardsii can be differentiated by the lack of a laterally projected T6 with a blunt tooth, a lack of dense tomentum on the basitarsi, and dull, finely punctate, weakly elevated discal areas on the terga (Gonzalez and Griswold 2013). Male A. edwardsii can be differentiated from all Anthidium by the presence of a pointed and narrow lateral lobe on T7, a brush of reddish-brown apical hairs on S4, and a laterally directed lateral lobe on S6 (Gonzalez and Griswold 2013).

Phenology

Anthidium edwardsii adults have been recorded in flight from April to October, with peak activity occurring from the last half of May to the first half of September (Gonzalez and Griswold 2013).

Host associations

Anthidium edwardsii is a generalist that has been observed visiting a variety of species within Apiaceae, Asclepiadaceae, Asteraceae, Boraginaceae, Cleomaceae, Convolvulaceae, Fabaceae, Lamiaceae, Onagraceae, Orobanchaceae, Plantaginaceae, Polygonaceae, and Verbenaceae (Gonzalez and Griswold 2013).

Nesting behavior

Anthidium edwardsii has been observed nesting in dead bamboo (Grigarick and Stange 1968).

Distribution

Anthidium edwardsii occur throughout Oregon, central Washington, southern Idaho, northern Utah, and in the Sierra Nevada of California, specifically in the Central Valley, Coast Ranges, and foothills. They are found primarily in the California chaparral, California woodlands, Central Valley grasslands, Sierra Nevada forests, Northern California coastal forests, Klamath-Siski forests, Snake-Columbia shrub steppe, and Great Basin shrub steppe (Gonzalez and Griswold 2013).


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

<p><em>Anthidium edwardsii</em> female face, photo: Tevan Brady</p>
Anthidium edwardsii female face, photo: Tevan Brady
<p><em>Anthidium edwardsii</em> female lateral habitus, photo: Tevan Brad</p>
Anthidium edwardsii female lateral habitus, photo: Tevan Brad
<p><em>Anthidium edwardsii</em> female abdomen, photo: Tevan Brady</p>
Anthidium edwardsii female abdomen, photo: Tevan Brady
<p><em>Anthidium edwardsii</em> female, diagram showing the dorsal view of the sixth tergite (T6), diagram from Gonzalez and Griswold 2013</p>
Anthidium edwardsii female, diagram showing the dorsal view of the sixth tergite (T6), diagram from Gonzalez and Griswold 2013
<p><em>Anthidium edwardsii</em> male face, photo: Tevan Brady</p>
Anthidium edwardsii male face, photo: Tevan Brady
<p><em>Anthidium edwardsii</em> male lateral habitus, photo: Tevan Brady</p>
Anthidium edwardsii male lateral habitus, photo: Tevan Brady
<p><em>Anthidium edwardsii</em> male abdomen, photo: Tevan Brady</p>
Anthidium edwardsii male abdomen, photo: Tevan Brady
<p><em>Anthidium edwardsii</em> male, ventral view of fourth sternum (S4), photo from Gonzalez and Griswold 2013</p>
Anthidium edwardsii male, ventral view of fourth sternum (S4), photo from Gonzalez and Griswold 2013
<p><em>Anthidium edwardsii</em> male, dorsal view of seventh tergum (T7), photo: Tevan Brady</p>
Anthidium edwardsii male, dorsal view of seventh tergum (T7), photo: Tevan Brady
<p><em>Anthidium edwardsii</em> male, diagram showing dorsal view of seventh tergum (T7), diagram from Gonzalez and Griswold 2013</p>
Anthidium edwardsii male, diagram showing dorsal view of seventh tergum (T7), diagram from Gonzalez and Griswold 2013
<p><em>Anthidium edwardsii</em> male, diagram showing ventral view of sixth sternum (S6), diagram from Gonzalez and Griswold 2013</p>
Anthidium edwardsii male, diagram showing ventral view of sixth sternum (S6), diagram from Gonzalez and Griswold 2013
<p><em>Anthidium edwardsii</em> male, diagram showing ventral view of seventh sternum (S7), diagram from Gonzalez and Griswold 2013</p>
Anthidium edwardsii male, diagram showing ventral view of seventh sternum (S7), diagram from Gonzalez and Griswold 2013
<p><em>Anthidium edwardsii</em> male, diagram showing ventral view of eighth sternum (S8), diagram from Gonzalez and Griswold 2013</p>
Anthidium edwardsii male, diagram showing ventral view of eighth sternum (S8), diagram from Gonzalez and Griswold 2013