Megachile (Sayapis)

Taxonomy

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

Overview

Megachile (Sayapis) are slender, narrow, parallel-sided bees with black integument on the head, thorax, and abdomen and pale apical bands on the terga (Mitchell 1937b; Michener 2007). They range in body length from 10–18 mm (Mitchell 1937b).

Diagnostic characteristics

(modified from Mitchell 1933; Michener 2007)

  • Tarsal claws usually with a sharp basal tooth.
  • Female mandible is four-toothed with or without an incomplete cutting edge in the second interspace and no cutting edge in the third interspace.
  • Female T6 with a projecting apical margin, which causes it to appear distally concave in profile.
  • Male abdomen has four exposed sterna in repose.
  • Male front coxa with a spine present.
  • Male front tarsi, usually light-colored, expanded, or highly modified.
  • Male mandible is three-toothed with a large, basal projection on the lower margin.
  • Male T6 preapical carina emarginate medially.
  • Male T6 apical margin with lateral teeth.

May be confused with

Megachile (Sayapis) may be superficially confused with bees within the subgenus Megachile (Chelostomoides) as both have narrow, parallel-sided abdomens (Michener 2007). Male Megachile (Sayapis) can be differentiated from Megachile (Chelostomoides) by the four exposed sterna in repose (Michener 2007). Female Megachile (Sayapis) can be differentiated from Megachile (Chelostomoides) by the mandible with a single cutting edge in the second interspace and nowhere else (Mitchell 1937b; Michener 2007).

Host associations

Megachile (Sayapis) are polylectic and have been recorded visiting multiple plant families, including Acanthaceae, Amaranthaceae, Apocynaceae, Aquifoliaceae, Arecaceae, Asteraceae, Boraginaceae, Cactaceae, Cleomaceae, Euphorbiaceae, Fabaceae, Lamiaceae, Lythraceae, Malvaceae, Olacaceae, Onagraceae, Plantaginaceae, Polemoniaceae, Polygonaceae, Rhamnaceae, Rubiaceae, Tamaricaceae, Verbenaceae, and Zygophyllaceae (Deyrup et al. 2002; Raw 2007).

Nesting behavior

Megachile (Sayapis) typically create nests using cut leaves and soil (mud or sand) in pre-existing cavities, although nesting behavior varies by species (Raw 2007). These bees have been observed nesting in a variety of both natural and man-made locations: Megachile zaptlana has been observed nesting in abandoned beetle burrows, M. cylindrica in Peruvian peppertree (Schinus polygamus) galls, M. policaris in adobe walls, and M. inimica in mesquite trees and fence posts (Raw 2007).

Diversity

Megachile (Sayapis) consists of 24 species, four of which occur in the U.S. (Raw 2007; Ascher and Pickering 2020).

Known invasives

There are no known invasives.

Distribution

Megachile (Sayapis) is native to North and South America, where they range from Canada to Argentina (Michener 2007).

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

<p><em>Megachile inimica </em>female face, photo: Jeni Sidwell</p>
Megachile inimica female face, photo: Jeni Sidwell
<p><em>Megachile inimica </em>female lateral habitus, photo: Jeni Sidwell</p>
Megachile inimica female lateral habitus, photo: Jeni Sidwell
<p><em>Megachile inimica </em>female abdomen, photo: Jeni Sidwell</p>
Megachile inimica female abdomen, photo: Jeni Sidwell
<p><em>Megachile inimica </em>male face, photo: Jeni Sidwell</p>
Megachile inimica male face, photo: Jeni Sidwell
<p><em>Megachile inimica </em>male lateral habitus, photo: Jeni Sidwell</p>
Megachile inimica male lateral habitus, photo: Jeni Sidwell
<p><em>Megachile inimica </em>male abdomen, photo: Jeni Sidwell</p>
Megachile inimica male abdomen, photo: Jeni Sidwell
<p><em>Megachile fidelis</em> male head, photo: Colleen Meidt</p>
Megachile fidelis male head, photo: Colleen Meidt
<p><em>Megachile fidelis</em> male front leg, photo: Colleen Meidt</p>
Megachile fidelis male front leg, photo: Colleen Meidt
<p><em>Megachile fidelis</em> male front leg, photo: Colleen Meidt</p>
Megachile fidelis male front leg, photo: Colleen Meidt
<p><em>Megachile cylindrica</em> female mandible, photo: Joshua Hengel</p>
Megachile cylindrica female mandible, photo: Joshua Hengel
<p><em>Megachile cylindrica</em> female mandible, photo: Joshua Hengel</p>
Megachile cylindrica female mandible, photo: Joshua Hengel
<p><em>Megachile fidelis</em> female T6, photo: Joshua Hengel</p>
Megachile fidelis female T6, photo: Joshua Hengel