Megachile (Addendella)


Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Megachile Latreille, 1802
Subgenus: Addendella Mitchell, 1980
Common name: none


Megachile (Addendella) are robust bees with black integument. They have primarily white hair on their body with some black hair on the head, scutum, scutellum, the discs of the terga, and S6 (Mitchell 1935b). Their body length ranges from 10–17 mm (Mitchell 1935b, Michener 2007). Megachile (Addendella) are univoltine, and adults have been observed flying from May to early July (Mitchell 1935b). This subgenus was previously synonymized with Megachile (Xanthosarus), but was revived by Gonzalez et al. 2019.

Diagnostic characteristics

(modified from Mitchell 1935b; Sheffield et al. 2011b)

  • Female clypeus distinctly and closely punctate with a crenulate or denticulate apical margin.
  • Female mandible four-toothed with an acute upper tooth. The cutting edge in the first interspace is incomplete and very small; the cutting edge in the second interspace is incomplete and large.
  • Female S2S5 with white scopal hairs.
  • Female T2T5 with carina of basal grooves strongly elevated.
  • Female T2T5 with black pubescence on the discs, contrasting with the white apical hair bands.
  • Female T6 strongly concave when viewed in profile.
  • Male front coxa with a spine that has a dense patch of red bristles at the base.
  • Male front tarsi simple, not modified or expanded.
  • Male mandible four-toothed (sometimes weakly) with a basal projection on the lower margin.
  • Male T6 preapical carina with wide median emargination.
  • Male T6 apical margin with lateral teeth but no sublateral teeth.

May be confused with

Megachile (Addendella) females can be confused with Megachile (Litomegachile) because of their similar four-toothed mandibles and concave T6 when viewed in profile. M. (Addendella) can be distinguished by their larger size and denticulate clypeal margin (Mitchell 1935b; Michener 2007). Male M. (Addendella) can look similar to Megachile (Argyropile) parallela in the wide emargination of the T6 preapical carina and the four-toothed mandibles. M. (Addendella) differ in their dense patch of red bristles at the base of the front coxa and the absence of sublateral spines on the apical margin of T6 (Mitchell 1935b).

Host associations

Megachile (Addendella) have been observed visiting the flowers of multiple plant families including Cactaceae, Ericaceae, Fabaceae, Hypericaceae, Onagraceae, and Plantaginaceae (Mitchell 1935b). They have also been shown to be effective pollinators of commercial cranberry (Cane et al. 1996). Females have been found cutting maple leaves (Acer rubrum) to line their nest cells, and males have been observed patrolling maple trees (Cane et al. 1996).

Nesting behavior

Megachile (Addendella) nest in the ground where they excavate their own nest cavity in the soil (Cane et al. 1996). The nests are usually shallow (4–17 cm) with a short main tunnel ending in horizontally arranged cells. Nest cells are lined with cut leaves and usually arranged singly or in groups of two, although they have sometimes been found arranged linearly, with 4–9 cells per nest (Cane et al. 1996).


Megachile (Addendella) includes a single species, Megachile addenda (Gonzalez et al. 2019).

Known invasives

There are no known invasives.


Megachile (Addendella) are known primarily from the eastern U.S. from southeastern Canada south to Florida (Mitchell 1935). They have been reported in the southern part ofthe U.S. as far west as California,but are mostly found east of Kansas (Mitchell 1935).

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


<p><em>Megachile addenda </em>female face, photo: Colleen Meidt</p>
Megachile addenda female face, photo: Colleen Meidt
<p><em>Megachile addenda </em>female lateral habitus, photo: Colleen Meidt</p>
Megachile addenda female lateral habitus, photo: Colleen Meidt
<p><em>Megachile addenda </em>female abdomen, photo: Colleen Meidt</p>
Megachile addenda female abdomen, photo: Colleen Meidt
<p><em>Megachile addenda </em>male face, photo: Colleen Meidt</p>
Megachile addenda male face, photo: Colleen Meidt
<p><em>Megachile addenda </em>male lateral habitus, photo: Colleen Meidt</p>
Megachile addenda male lateral habitus, photo: Colleen Meidt
<p><em>Megachile addenda </em>male abdomen, photo: Colleen Meidt</p>
Megachile addenda male abdomen, photo: Colleen Meidt