Tribe Megachilini

Genus Megachile, 26 taxa

    This is a very diverse genus whose species are abundant throughout Florida. All of the species are moderate to large sized bees with black bodies and white, rarely golden, hairs. Females of most subgenera cut leaves to line their nests, which may be in the ground or in premade holes in vegetation. Chelostomoides and the introduced Callomegachile use resin. The following subgenera (number of species in parentheses) known from Florida, Acentron (1), Argyropile (2), Callomegachile (1), Chelostomoides (4), Eutricharaea (1), Leptorachis (1), Litomegachile (3), Megachiloides (5), Melanosarus (2), Pseudocentron (1), Pseudomegachile (1), Sayapis (3), and Xanthosarus (2). None of the species is endemic to Florida. Many are widespread in the eastern United States or common along the SE coastal plain. Three species are introduced (M. concinna, M. lanata, M. sculpturalis). While most species are widespread and likely occur throughout the state, two species are geographically restricted to South Florida (M. bahamensis and M. lanata). Many are polylectic with legumes and composites favorite pollen sources. Most have long flight periods, although members of the subgenus Megachiloides have more restricted flight periods.

Keys to subgenera of Megachile known from Florida (modified from Michener 2000)


  1. S6 with at least posterior half bare or nearly so, except for subapical row of short hairs, behind which is bare, smooth rim, directed posteriorly (body megachiliform)..2
  2. Meg xyl F termvent
    Meg pet F termvent
    Meg alb F term

    S6 with well-dispersed scopal hairs, or, if partly bare, then without bare apical rim behind transverse fringe of short hairs, or (in Argyropile) rim directed upward, or rim narrow and barely recognizable..5

    Meg camp F stern
    Meg par F term

  3. Mandible five-toothed, a long cutting edge in second interspace, none elsewhere..M. (Melanosarus)
  4. Meg xyl F mandclyp

    Mandible four-toothed, a well-formed cutting edge in third interspace..3

    Meg alb F mand

  5. Second interspace distinct, with cutting edge usually present..M. (Pseudocentron)
  6. megprufemalemandiblesclose.JPG (88344 bytes)

    Second interspace lacking or small, without cutting edge..4

    Meg alb F mand

  7. Mandible more robust, apical tooth more protuberant, much broader than other teeth; gena usually broader than eye in lateral view. .M. (Acentron)
  8. Meg alb F mand

    Mandible less robust, apical tooth not much broader than second or third; gena usually narrower..M. (Leptorachis)

    Meg pet F mandclyp
    Meg pet F genapleur

  9. Mandible without cutting edges between teeth, or with incomplete cutting edge in second interspace only; mandible with less than five teeth, or if five toothed, then upper two teeth (4 and 5) usually closer together than teeth 3 and 4..6
  10. Mandible with cutting edges between teeth, if in second interspace only, then edge complete (in three toothed mandible) or mandible clearly five-toothed, with teeth 4 and 5 about as far apart as 3 and 4...9

  11. Mandible with incomplete cutting edge in second interspace, and no cutting edge elsewhere..M. (Sayapis)
  12. Meg pol F mandclyp

    Mandible without cutting edges..7

    Meg geor F mandclyp

  13. Pubescence largely white, not fulvous, forming narrow white apical bands on metasomal terga and sometimes narrow bands on postgradular grooves..M. (Chelostomoides)
  14. Meg exil F abddor

    Pubescence with large areas of black or fulvous, forming striking color pattern ..8

    Meg scu F dorhab

  15. Mandibular carinae minutely roughened, sometimes dull..M. (Callomegachile)

    Mandibular carinae shining and smooth..M. (Pseudomegachile)

  16. S6 with apical rim directed upward beyond fringe of hairs, this rim conspicuous if tergum and sternum are spread apart. .M. (Argyropile)
  17. Meg par F term

    S6 without apical rim, or, if rim present, than directed posteriorly and usually inconspicuous..10

    Meg mend F termlat

  18. Mandible three-toothed or median tooth weakly divided and mandible thus obscurely four-toothed, with cutting edge limited to upper interspace (Second if mandible tridentate, third if mandible quadridentate)..M. (Megachiloides, in part)
  19. Mandible four- or five-toothed, with cutting edges in third and usually second interspaces, or rarely in second only..11

  20. Metasomal sterna with entire and copious white apical hair fasciae beneath scopa. .M. (Eutricharaea)
  21. Meg con F stern

    Metasomal sterna with white hair fasciae absent or broadly interrupted medially..12

  22. Mandible four-toothed, upper tooth acute or right-angular..13
  23. Mandible four or five-toothed, but if four-toothed, then upper tooth rounded, truncate, or incised (sometimes only minutely) and thus approaching the five-toothed condition..M. (Xanthosarus

    Meg add F mandclyp
  24. T6 straight in profile; mandible with second tooth often rounded or obtuse, usually no cutting edge in second interspace..M. (Megachiloides, in part)
  25. Meg rubi F termlat
    Meg integrla F mandclyp

    T6 usually concave in profile; mandible with second tooth acute, a small beveled cutting edge in second interspace..M. (Litomegachile), also includes M. addenda (Xanthosarus).

    Meg pseu F termlat
    Meg mend F termlat
    Meg tex F termlat
    Meg add F termlat
    Meg pseu F mandclyp


  1. Middle tibial spur absent or much shorter than apical width of tibia, sometimes immovably fused to tibia, and middle basitarsus not or little modified..2
  2. Middle tibial spur present, articulated to the tibia, about as long as apical tibial width, or, if absent, (as in some species of Xanthosarus), then middle basitarsus modified and swollen..5

  3. Middle tibial spur present, articulated, but small..M. (Leptorachis)
  4. Middle tibial spur absent or represented by prong immovably fused to tibia...3

  5. Middle tibia with a spur like apical prong (Spur presumably fused to tibia), prong sometimes reduced to large, acute tooth..M. (Pseudocentron)
  6. Meg pru M legsvent

    Middle tibia without such a process..4

  7. Scutum finely and densely rugoso-punctate, punctures not individually distinguishable..M. (Acentron)
  8. Meg alb M vertscut

    Punctures of scutum usually well separated, but, if close, then individually distinguishable..M. (Melanosarus)

    Meg xyl M vertscut

  9. S4 not exposed or only its posterior margin exposed; punctation and vestiture of S4 (except sometimes for posterior margin) reduced and different from those of S3..M. (Chelostomoides)
  10. Meg exil M stern
    Meg geor M stern

    S4 exposed, thus four exposed sterna, punctation and vestiture of S4 similar to those of S3..6

  11. S8 with hairs on lateral margin, body chalicodomiform, with large areas of black or fulvous hairs forming a striking color pattern..7

    meglantop.GIF (385004 bytes)

    S8 without marginal hairs, but discal hairs sometimes extending laterally beyond margin; body usually megachiliform, usually without a striking color pattern..8

  12. T6 with carina short, low, not or shallowly emarginate, not denticulate ..Callomegachile

    Meg scu M termdor

    T6 with carina strong, , strongly dentate or denticulate, or sometimes scarcely undulate..M. (Pseudomegachile)

  13. Metasoma about twice as long as wide (Carina of T6 usually emarginate medially; front tarsus usually enlarged and pale; front coxa with spine and usually with red bristle)..Sayapis
  14. Meg pol M abddor
    Meg pol M legsdor
    Meg pol M headvent

    Metasoma less than twice as long as wide..9

    Meg mend M abddor

  15. Mandible four-toothed..10
  16. Meg add M mandclyp
    Meg par M mand

    Mandible three-toothed..11

    Meg mend M mandclyp

  17. Front coxa usually largely bare anteriorly, often with patch of short, red bristles in front of spine, front tarsus frequently modified, pallid (holarctic)..M. (Xanthosarus

    Meg add M headvent

    Front coxa hairy, without red bristles; front tarsus simple, dark colored (Neartic)..M. (Argyropile)

    Meg par M headthorvent
    Meg par M lathab

  18. Morphological apical margin (not carina) of T6 without evident teeth..M. (Eutricharaea)
  19. Morphological apical margin of T6 with four small but distinct teeth..M. (Litomegachile)

    Meg mend M term