Megachile (Xanthosarus)

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Megachile Latreille, 1802
Subgenus: Xanthosarus Titus, 1906
Common name: none

Overview

Megachile (Xanthosarus) are robust bees with black integument and varying hair color that can be gray, orange-red, yellow, white, or entirely black (Michener 2007; Gonzalez 2008; Praz 2017). Megachile (Xanthosarus) range in body length from 8–18 mm (Michener 2007).

Diagnostic characteristics

(modified from Mitchell 1936; Mitchell 1943; Mitchell 1980; Gonzalez 2008; Praz 2017)

Female clypeus is finely and densely punctate.
Female mandible is broad with 5 teeth.
Female mandible with cutting edge between the third and fourth teeth.
Female mandible second interspace with either no cutting edge or sometimes a partial cutting edge.
Female sterna lack apical bands of hair under the scopa.
Female T6 rounded apically.
Female T6 pubescence are erect.
Male gonoforceps can be apically enlarged and bifid or simple and dilated.
Male front coxa with developed spine.
Male front tarsus is expanded and pale yellow or white with a long fringe of hair ventrally.
Male mid-basitarsus is often modified or swollen.
Male mid-tibia usually lacks an apical spur.
Male mandible with 3–4 teeth.
Male mandible with an inferior projection that is long, narrow, truncate, and pointed posteriorly.
Male S4 apical margin with a small median tubercle.
Male T6 apical margin lacks a lateral teeth.
Male T6 preapical carina is bilobed, medially emarginate, or denticulate.
Male T6 without tomentum above the preapical carina, or, if present, with hairs only present medially.
Male T7 large and produced medially to a small tooth.

May be confused with

Megachile (Xanthosarus) may be confused with the subgenus Megachile (Phaenosarus) due to the similar structure of the mandible (Michener 2007). Megachile (Xanthosarus) can be differentiated from Megachile (Phaenosarus) by the pubescence on T6 and length of S6. Megachile (Xanthosarus) have erect pubescence to the tip of T6, while Megachile (Phaenosarus) have appressed pubescence on the apical half of T6 (Mitchell 1936). Megachile (Xanthosarus) S6 does not protrude beyond the apex of the tergum, which is short, broad, and apically rounded (Mitchell 1936). In contrast, Megachile (Phaenosarus) S6 extends beyond the apex of the tergum, which is long with a narrowly rounded tip (Mitchell 1936).

Host associations

Megachile (Xanthosarus) have been observed visiting flowers within the families Asteraceae, Apocynaceae, Campanulaceae, Caprifoliaceae, Cleomaceae, Convolvulaceae, Ericaceae, Fabaceae, Lamiaceae, Loasaceae, Onagraceae, Plantaginaceae, Polygonaceae, and Verbenaceae (Mitchell 1936; Güler and Çağatay 2006).

Nesting behavior

Megachile (Xanthosarus) nest in pre-existing cavities in wood, sandy soil, and abandoned nests of Anthophora bees (Gonzalez 2008). Females have also been observed digging burrows underground and in decaying wood (Westrich 1989). They use small circular leaves to construct the base of their brood cells (Williams et al. 1986; Krombein and Norden 1995).

Diversity

Megachile (Xanthosarus) includes 41 species, 15 of which occur in North America (Raw 2007; Nagase 2011).

Known invasives

There are no known invasives.

Distribution

Megachile (Xanthosarus) are broadly distributed across the northern hemisphere. They are found in North America, Europe, northern Africa, and Asia. In North America, they can be found from Canada to Mexico (Mitchell 1936; Michener 2007).

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