Schizomegachile

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Megachilini
Genus: Schizomegachile Michener, 1965
Common name: none

Overview

The single species in this genus, Schizomegachile monstrosa, has a black integumentintegument:
a tough, protective outer layer
and sparse white hairs throughout its body (Houston 2018Houston 2018:
Houston, T.F. 2018. A guide to the native bees of Australia. CSIRO Publishing, Clayton Australia, 280 pp.
). They range in body length from 17–22 mm (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
). Schizomegachile had previously been considered a subgenus of Megachile but was elevated to genus status by Gonzalez et al. (2019).

Diagnostic characteristics

(modified from Michener 1965Michener 1965:
Michener, C.D. 1965. A classification of the bees of the Australian and South Pacific regions. Bulletin of the American Museum of Natural History 130: 1-362.
; Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
)

  • Preoccipital carinacarina:
    a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
    present laterally.
  • Pronotal lobe pronotal lobe:
    a part of the pronotum located dorsally on the posterior margin of the pronotum and overlaps the anterior thoracic spiracle
    with lamellatelamellate:
    thin, plate-like, often somewhat translucent structure
    carinacarina:
    a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
    .
  • Female tarsal claws three-toothed.
  • Female S6S6:
    the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
    with a median ridge.
  • Female T6T6:
    the segments on the top side of the abdomen, often abbreviated when referring to a specific segment to T1, T2, T3, T4, T5, T6, or T7
    has a shiny, flat-topped longitudinal ridge.
  • Male front tarsustarsus:
    the group of segments at the end of the leg following the tibia
    is enlarged and pale.
  • Male hind tibiatibia:
    the segment of the leg, between the femur and the tarsus
    lacks spurs, but has a single large apicalapical:
    near or at the apex or end of any structure
    spine.
  • Male mandiblemandible:
    bee teeth, so to speak, usually crossed and folded in front of the mouth
    is bidentatebidentate:
    having two teeth
    with a transparent basalbasal:
    originating at the foundation of a structure
    lamella.
  • Male S4S4:
    the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
    is exposed, and less hairy and smoother than S3S3:
    the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
    .
  • Male S6S6:
    the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
    divided by a broad median membranous region.

May be confused with

Schizomegachile may be confused with Hackeriapis as they have similar coloration, females share a similar mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
and clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
shape, and the males of both groups have three exposed sternites (Michener 1965Michener 1965:
Michener, C.D. 1965. A classification of the bees of the Australian and South Pacific regions. Bulletin of the American Museum of Natural History 130: 1-362.
). However, Schizomegachile females have three-toothed tarsal claws and a projection on S6S6:
the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
(Michener 1965Michener 1965:
Michener, C.D. 1965. A classification of the bees of the Australian and South Pacific regions. Bulletin of the American Museum of Natural History 130: 1-362.
). Schizomegachile males have bidentatebidentate:
having two teeth
mandibles, lack hind tibial spurs (and instead have an immovable spine), and do not have teeth on the apicalapical:
near or at the apex or end of any structure
margin of T6T6:
the segments on the top side of the abdomen, often abbreviated when referring to a specific segment to T1, T2, T3, T4, T5, T6, or T7
(Michener 1965Michener 1965:
Michener, C.D. 1965. A classification of the bees of the Australian and South Pacific regions. Bulletin of the American Museum of Natural History 130: 1-362.
).

Host associations

Schizomegachile are known to visit flowers of plants in the family Myrtaceae (Houston 2018Houston 2018:
Houston, T.F. 2018. A guide to the native bees of Australia. CSIRO Publishing, Clayton Australia, 280 pp.
).

Nesting behavior

Schizomegachile nest in pre-existing cavities and have been observed nesting in bamboo trap nests (Houston 2018Houston 2018:
Houston, T.F. 2018. A guide to the native bees of Australia. CSIRO Publishing, Clayton Australia, 280 pp.
). They use masticated plant material in the construction of their nests and partitions between nest cells (Houston 2018Houston 2018:
Houston, T.F. 2018. A guide to the native bees of Australia. CSIRO Publishing, Clayton Australia, 280 pp.
).

Diversity

Schizomegachile consists of one species, S. monstrosa (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
); this species is not known to occur in the U.S. or Canada.

Known invasives

There are no known invasives. 

Distribution

Schizomegachile occurs in the temperate regions of eastern and western Australia (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
).

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

References

Gonzalez, V.H., G.T. Gustafson, and M.S. Engel. 2019. Morphological phylogeny of Megachilini and the evolution of leaf-cutter behavior in bees (Hymenoptera: Megachilidae). Journal of Melittology (85): 1-123.

Houston, T.F. 2018. A guide to the native bees of Australia. CSIRO Publishing; 280 pp.

Michener, C.D. 1965. A classification of the bees of the Australian and South Pacific regions. Bulletin of the AMNH 130, 339 pp.

Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.