Megachile #40; Chaetochile #41;

Taxonomy

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

Overview

Megachile (Chaetochile) are large bees with black integumentintegument:
a tough, protective outer layer
covered in long, dense yellowish-white and black hair, and they have pale apicalapical:
near or at the apex or end of any structure
hair bandsbands:
usually referring to bands of hair or bands of color that traverse across an abdominal segment
on their tergaterga:
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
(Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.). They range in body length from 10–14 mm (Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.). Megachile (Chaetochile) was previously synonymized with Megachile (Dasymegachile), but was resurrected by Gonzalez et al. 2019Gonzalez et al. 2019:
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..

Diagnostic characteristics

(modified from Mitchell 1980Mitchell 1980:
Mitchell, T.B. 1980. A generic revision of the megachiline bees of the Western Hemisphere. Department of Entomology, North Carolina State University, 95 pp.; Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.)

Female clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
with flat, erect, hooked hairs.
Female mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
four-toothed, with the innermost tooth notched and with an incomplete cutting edge in the second interspace and a long cutting edge in the third.
Female scopascopa:
modified hairs for carrying pollen; often branched and dense hairs on the hind-leg, or on the ventral surface of the abdomen in Megachilidae
black.
Male antenna with F1 nearly equal in length to F2.
Male mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
three-toothed, with the second tooth truncatetruncate:
ending abruptly, or squared off
, occasionally notched, and closer to the first tooth than the third.
Male mandiblemandible:
bee teeth, so to speak, usually crossed and folded in front of the mouth
without a basalbasal:
originating at the foundation of a structure
process on the lower margin.
Male front coxacoxa:
the basal segment of the leg
without a tooth or projection.
Male 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
with preapicalpreapical:
referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
emarginate medially and the area in front of the carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
is distinctly depressed.
Male 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
apicalapical:
near or at the apex or end of any structure
margin with two flat projections and laterallateral:
relating, pertaining, or attached to the side
spines.

May be confused with

Megachile (Chaetochile) are most similar to M. (Dasymegachile) in their size and long dense hair. Female M. (Chaetochile) can be differentiated by their flat clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
with erect, hooked hair. Male M. (Chaetochile) can be identified by their middle mandibularmandibular:
near the mandible
tooth, which is truncatetruncate:
ending abruptly, or squared off
or notched and closer to the first tooth. The teeth of M. (Dasymegachile) are acute and equidistant from each other (Mitchell 1980Mitchell 1980:
Mitchell, T.B. 1980. A generic revision of the megachiline bees of the Western Hemisphere. Department of Entomology, North Carolina State University, 95 pp.; Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.).

Host associations

Megachile (Chaetochile) has been reported on Lathyrus macropus (Fabaceae) (Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.).

Nesting behavior

Nesting behavior is unknown.

Diversity

Megachile (Chaetochile) includes a single species, Megachile schwimmeri (Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.; Engel 2017Engel 2017:
Engel, M.S. 2017. Replacement names for bees in the tribe Megachilini (Hymenoptera: Megachilidae). Journal of Melittology 70: 1-5.).

Known invasives

There are no known invasives.

Distribution

Megachile (Chaetochile) are known from Argentina, Brazil, and Peru (Durante and Abrahamovich 2006Durante and Abrahamovich 2006:
Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.).

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

References

Durante, S.P., and A.H. Abrahamovich. 2006. Redescription of Chaetochile as subgenus of Megachile (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 132(1): 103-109.

Engel, M.S. 2017. Replacement names for bees in the tribe Megachilini (Hymenoptera: Megachilidae). Journal of Melittology 70: 1-5.

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): Evolution of leaf-cutter behavior in bees. Journal of Melittology 85: 1-123.

Mitchell, T.B. 1980. A generic revision of the megachiline bees of the Western Hemisphere. Department of Entomology, North Carolina State University, 95 pp.

Megachile (Chaetochile)