Tribe Bombini (seven taxa)

Genus Bombus, seven taxa

    According to Milliron, B. fervidus does not occur in Florida. Identifications of males of this species are likely to be B. pensylvanicus. Mitchell also notes this common mistake. I have not seen any definite specimens of B. fervidus from Florida. Mitchell also lists B. terricola from Florida but no specimens have been seen to confirm this. Milliron’s map shows B. terricola to extend southward to about North Georgia along the higher elevations of the Appalachian mountains. It is unlikely that this species occurs in Florida. B. affinis is also found in a similar distribution but does not likely extend into Florida. Thus, this key does not include these 3 species. From personal experience collecting in both South Florida (Everglades National Park) and North Florida (Tall Timbers in Leon County, St. Marks Wildlife Refuge in Wakulla County, and Osceola National Forest in Baker and Columbia counties, Bombus impatiens, Bombus pensylvanicus, and Bombus fraternus are the three most common species. Bombus griseocollis, B. bimaculatus and Bombus nevadensis auricormis appear to be rarer. Bombus variabilis was classified as Psithyrus variabilis in Mitchell's book. Recent phylogenetic studies place this group of parasitic bees within the Bombus lineage (Michener 2000).

Keys to Queens, Workers, and Males (from Mitchell 1962)

Key to Queens

  1. Hind tibiae with well developed corbiculae…..2
  2. bomfraqueenscopa.JPG (62780 bytes)

    Hind tibiae relatively slender, rather uniformly pubescent throughout….Subgenus Psithyrus, Bombus variabilis (these are the females in this group, no workers present)

  3. Laterall ocelli distinctly below supraorbital line….3
  4. bomfraqueenocelli.JPG (61695 bytes)

    Laterall ocelli located at or near level of supraorbital line….5

    bompenqueenocelli.JPG (75260 bytes)

  5. Malar space longer than width of mandible at base…Subgenus Bombias, Bombus nevadensis auricormis
  6. Malar space shorter than width at base of mandibles….Subgenus Pyrobombus, 4

    bomgriqueenmalarspace.JPG (50521 bytes) bomfraqueenmalarspace.JPG (61943 bytes)

  7. Dorsum of thorax without an interalar black band, usually with a very small median area of black pubescence…Bombus griseocollis
  8. bomgriqueenscutum2.JPG (57018 bytes)

    Dorsum of thorax usually with a conspicuous, transverse band of black pubescence between the wing bases…Bombus fraternus

    bomfraqueentop.JPG (45660 bytes)

  9. Posterior half of scutum and all of scutellum black pubescent, Subgenus Megabombus, Bombus pensylvanicus pensylvanicus>

bompenqueentop.JPG (41134 bytes)

    Posterior portion of dorsum of thorax with some yellow pubescence…Subgenus Bombus, 6

    bomimpqueentop.JPG (43692 bytes)

  1. Tergum 2 of abdomen entirely black pubescent…Bombus impatiens

bomimpqueenterga.JPG (51180 bytes)

Tergum 2 of abdomen largely black pubescent, with a limited amount of yellow medially at base…Bombus bimaculatus

bombimqueentop2.JPG (45607 bytes)

Key to workers

  1. Hind tibiae with well developed corbiculae…..2
  2. bomfraworkercorbicula.JPG (53984 bytes)

    Hind tibiae relatively slender, rather uniformly pubescent throughout….Subgenus Psithyrus, Bombus variabilis (there are no true workers in this group, females show no disinct size differences between queens and workers)

  3. Laterall ocelli distinctly below supraorbital line….3
  4. bomgriworkerocelli.JPG (60350 bytes)

    Laterall ocelli located at or near level of supraorbital line….5

    bompenworkerocelli2.JPG (63763 bytes)

  5. Malar space fully equal in length to basal width of mandible; scutellum black pubescent…Subgenus Bombias, Bombus nevadensis auricormis
  6. Malar space much shorter than basal width of mandible; scutum or tergum 3 with black pubescence…4

    bomgriworkermalarspace.JPG (78165 bytes) bomfraworkertop.JPG (44890 bytes)

  7. Dorsum of thorax with a distinct interalar black band; tergum 2 entirely covered with yellow pubescence.. Bombus fraternus
  8. bomfraworkertop.JPG (44890 bytes) bomfraworkerterga1&2.JPG (57137 bytes)

    Dorsum of thorax with no interalar band; tergum 2 narrowly black on apical margin, otherwise yellow, slightly tinged with brown..Bombus griseocollis

    bomgriqueenscutellum.JPG (59648 bytes) bomgriqueenterga1&2_2.JPG (52049 bytes)

  9. Posterior half of scutum and all of scutellum black pubescent, Subgenus Megabombus, Bombus pensylvanicus pensylvanicus
  10. bompenworkerscutum.JPG (48295 bytes)

    Scutellum largely or entirely yellow pubescent…Subgenus Bombus, 6

    bomimpworkerscutum2.JPG (40496 bytes)

  11. Abdominal terga 2 to 6 entirely black pubescent, with only tergum 1 yellow; malar space shorter than basal width of mandible…Bombus impatiens

bomimpworkerterga1&2.JPG (42406 bytes) bomimpworkermalarspace.JPG (53005 bytes)

Abdominal tergum 2 largely black pubescent, but invaded by yellow along basal margin medially; malar space fully equal to width of mandible at base…Bombus bimaculatus

bombimworkerterga.JPG (51452 bytes) bombimworkermalarspace.JPG (58182 bytes)

Key to males

  1. Hind tibiae convex, quite densely pubescent on outer surface, gonostylus more elongate, much exceeding apex of gonocoxites…Subgenus Psithyrus, Bombus variabilis
  2. bomvarmalegenitalia5.JPG (39752 bytes)

    Hind tibiae somewhat flattened, rather sparsely pubescent on outer surface; gonostylus of genital armature very short, not much exceeding apex of gonocoxite…2

    bompenmalegenitaliaventral2.JPG (40317 bytes)

  3. Eyes usually converging above, the lateral ocelli nearer to margins of the eyes than to each other; malar space very short, length one-fourth or less the basal width of the mandible….3
  4. bomgrimaleocelli.JPG (60587 bytes) bomgrimalemalarspace.JPG (52042 bytes)

    Eyes about parallel, the lateral ocelli distant from eye margin; malar space nearly or quite as long as basal width of mandible….5

    bompenmalefaceclose.JPG (53967 bytes) bompenmalemalarspace.JPG (55389 bytes)

  5. Malar space exceedingly short, almost obliterated, eyes nearly touching base of mandibles, strongly convergent above…Bombus fraternus
  6.  bomframalemalarspace.JPG (54728 bytes) bomframalevertex.JPG (60876 bytes)

    Malar space distinct, even though short, eyes somewhat removed from base of mandibles…4

    bomgrimalemalarspace.JPG (52042 bytes)

  7. Eyes nearly parallel, even though face very narrow, with ocelli nearer margin of vertex than to antennae…Bombus griseocollis
  8. bomgrimaleface.JPG (45127 bytes) bomgrimaleocelli.JPG (60587 bytes)  

    Eyes strongly convergent above, ocelli located midway between antennae and hind margin of vertex…Bombus nevadensis auricormis

  9. Malar space not much longer than wide, about a fourth the length of the eye; abdominal tergum 5 usually black pubescent (many specimens from Florida have yellow pubescence, though!)..Bombus pensylvanicus pensylvanicus
  10. bompenmalemalarspace.JPG (55389 bytes) bompenmaleterga.JPG (42612 bytes) bompenmalegenitaliadorsal.JPG (45162 bytes)

    Malar space considerably longer than wide, about one third of the length of the eye; tergum yellow pubescent…Sugenus Bombus, 6

    bomimpmalemalarspace.JPG (55460 bytes)

  11. Segment 2 of abdomen entirely black pubescent; malar space shorter than width of mandible at base..Bombus impatiens

bomimpmaleterga.JPG (50996 bytes) bomimpmalemalarspace.JPG (55460 bytes)

Segment 2 of abdomen with at least some yellow pubescence; malar space longer than width of mandible at base…Bombus bimaculatus

bombimmaleterga.JPG (47426 bytes) bombimmalemalarspace.JPG (51187 bytes)


Subgenus Megabombus, 1 taxa

Apidae: Bombus pensylvanicus pensylvanicus De G.

County Records: Alachua, Broward, Charlotte, Citrus, Collier, Miami-Dade (From Milliron); Baker, Columbia, Leon, Wakulla (Pascarella unpub. data).

bompen.jpg (72338 bytes)

Locations: Altamonte, Bonita Springs, Crystal River, Everglades, Ft. Lauderdale, Gainesville, Homestead, Pinecrest, Punta Gorda (from Milliron)

Dates: Mid-February to late November

Plants: polylectic

Notes: One of the most common species. Extends all the way to the tip of the peninsula. Unknown from the keys. Probably occurs throughout Florida.



  bompenqueenface.JPG (62102 bytes) bompenqueenclypeus.JPG (67222 bytes) bompenqueenlabrum.JPG (59635 bytes) bompenqueenmandibles.JPG (55951 bytes) bompenqueenmalarspace.JPG (54483 bytes) bompenqueenmalarspace2.JPG (66426 bytes) bompenqueenocelli.JPG (75260 bytes) bompenqueenocelli2.JPG (60040 bytes) bompenqueenocelli3.JPG (43993 bytes)

bompenqueentop.JPG (41134 bytes) bompenqueenvertex.JPG (40226 bytes) bompenqueenside.JPG (39956 bytes) bompenqueenwing.JPG (49832 bytes) bompenqueenterga.JPG (48814 bytes) 

bompenqueen1tergacornerhairs.JPG (61427 bytes) bompenqueenlegs.JPG (41468 bytes) bompenqueenhindbasitarsus.JPG (37147 bytes) bompenqueencorbicula.JPG (59948 bytes)


  bompenworkerface.JPG (57865 bytes) bompenworkermandible.JPG (54904 bytes) bompenworkermalarspace.JPG (57527 bytes) bompenworkerocelli.JPG (60126 bytes) bompenworkerocelli2.JPG (63763 bytes) bompenworkervertex.JPG (41569 bytes) bompenworkerwings.JPG (37518 bytes) bompenworkertop.JPG (42557 bytes) bompenworkerside.JPG (48327 bytes) bompenworkerscutum.JPG (48295 bytes) bompenworkerscutellum.JPG (48637 bytes) bompenworkerterga.JPG (42575 bytes) 


  bompenmaleface.JPG (41257 bytes) bompenmalefaceclose.JPG (53967 bytes) bompenmaleclypeus.JPG (50180 bytes) bompenmalemalarspace.JPG (55389 bytes) bompenmalevertex.JPG (55789 bytes) bompenmaleside.JPG (42933 bytes) bompenmaleside2.JPG (39513 bytes) bompenmalewing.JPG (40367 bytes) bompenmalescutum.JPG (46833 bytes) bompenmalescutumside.JPG (33940 bytes) bompenmaleterga.JPG (42612 bytes) bompenmalesterna.JPG (55578 bytes) bompenmalegenitaliadorsal.JPG (45162 bytes) bompenmalegenitaliadorsal2.JPG (36975 bytes) bompenmalegenitaliadorsal3.JPG (34691 bytes) bompenmalegenitaliaside.JPG (35233 bytes) bompenmalegenitaliaside2.JPG (33721 bytes) bompenmalegenitaliaventral.JPG (46329 bytes) bompenmalegenitaliaventral2.JPG (40317 bytes) 


Subgenus Bombias Robertson

Apidae: Bombus nevadensis auricormis Robertson

County Records: None from the FSCA. Milliron’s map shows it occurring throughout Florida



Plants: polylectic

Notes: Specimens of this species have not been seen. No photos are available at this time. Perhaps it has been confused with other species?



Subgenus Bombus, 2 taxa

Apidae: Bombus impatiens Cresson

County Records: Baker, Columbia, Leon, Miami-Dade (rare), Wakulla

bomimp.jpg (70995 bytes)


Dates: January-November

Plants: polylectic

Notes: The map above is surprising given the abundance of this common species. It likely occurs throughout Florida.



  bomimpqueenfront.JPG (44857 bytes) bomimpqueenclypeus.JPG (61782 bytes) bomimpqueenmandible.JPG (59816 bytes) bomimpqueenmalarspace.JPG (61737 bytes) bomimpqueenocelli.JPG (61273 bytes) bomimpqueenvertex.JPG (45854 bytes) bomimpqueenvertexside.JPG (32541 bytes) bomimpqueenside.JPG (48610 bytes) bomimpqueenside2.JPG (45112 bytes) bomimpqueenside3.JPG (44041 bytes) bomimpqueentop.JPG (43692 bytes) bomimpqueenscutum.JPG (42200 bytes) bomimpqueenterga.JPG (51180 bytes) bomimpqueenterga2.JPG (54143 bytes) bomimpqueenrearleg.JPG (50262 bytes) bomimpqueenrearbasitarsus.JPG (64786 bytes) bomimpqueenwing.JPG (46419 bytes)


bomimpworkerfront.JPG (54916 bytes) bomimpworkerlabrum.JPG (59749 bytes) bomimpworkermalarspace.JPG (53005 bytes)bomimpworkerocelli.JPG (48479 bytes) bomimpworkervertexside.JPG (35193 bytes) bomimpworkerside.JPG (41097 bytes) bomimpworkerside2.JPG (46356 bytes) bomimpworkertop.JPG (46542 bytes) bomimpworkerscutum.JPG (38062 bytes) bomimpworkerscutum2.JPG (40496 bytes) bomimpworkerterga1&2.JPG (42406 bytes) bomimpworkerwing.JPG (35793 bytes)


bomimpmalefront.JPG (44137 bytes) bomimpmaleclypeus.JPG (53145 bytes) bomimpmalemalarspace.JPG (55460 bytes) bomimpmalemalarspace2.JPG (59489 bytes) bomimpmaleocelli.JPG (51419 bytes)

bomimpmalevertexside.JPG (35289 bytes) bomimpmaleside.JPG (42766 bytes) bomimpmalewing.JPG (35522 bytes) bomimpmaletop.JPG (41132 bytes) bomimpmaleterga.JPG (50996 bytes)

bomimpmaleterga1.JPG (54898 bytes) bomimpmalegenitaliasideclose.JPG (48322 bytes) bomimpmalegenitaliadorsalclose.JPG (38408 bytes) bomimpmalegenitaliaventralclose.JPG (52386 bytes)


Apidae: Bombus bimaculatus Cresson

County Records: Alachua, Baker, Clay, Franklin, Lake, Levy, Highlands, Okaloosa, Wakulla

bombim.jpg (71588 bytes)


Dates: Feb.-September

Plants: polylectic

Notes: This species might be limited to the panhandle and southward to the central peninsula. 



bombimqueenface.JPG (46778 bytes) bombimqueenclypeus.JPG (61128 bytes) bombimqueenmandible.JPG (45783 bytes) bombimqueenmalarspace.JPG (48608 bytes) bombimqueenvertex.JPG (51657 bytes)

bombimqueenvertexhairs.JPG (38200 bytes) bombimqueentop.JPG (44902 bytes) bombimqueentop2.JPG (45607 bytes) bombimqueenside.JPG (36305 bytes) bombimqueenwing.JPG (39563 bytes)

bombimqueenscutum.JPG (45473 bytes) bombimqueenscutum2.JPG (44180 bytes) bombimqueenmidtarsi.JPG (45815 bytes) bombimqueenscopa.JPG (46379 bytes) 


bombimworkerface.JPG (49453 bytes) bombimworkermandible.JPG (55477 bytes) bombimworkermalarspace.JPG (58182 bytes) bombimworkermalarspace2.JPG (61662 bytes) bombimworkerocelli.JPG (59801 bytes)

bombimworkerocelli2.JPG (49001 bytes) bombimworkervertexhairs.JPG (53960 bytes) bombimworkervertexhairstop.JPG (49270 bytes) bombimworkervertexside.JPG (41917 bytes) bombimworkerside.JPG (56875 bytes)

bombimworkerwing.JPG (40192 bytes) bombimworkerscutum.JPG (44715 bytes) bombimworkerterga.JPG (51452 bytes) bombimworkerterga1&2.JPG (61525 bytes) bombimworkertergaandtarsi.JPG (60271 bytes)

bombimworkerscopa.JPG (35140 bytes) bombimworkerscopa2.JPG (31500 bytes) 


bombimmalefront.JPG (39618 bytes) bombimmalefaceside.JPG (39103 bytes) bombimmalecheek.JPG (38453 bytes) bombimmalelabrum.JPG (43397 bytes) bombimmalemalarspace.JPG (51187 bytes)

bombimmalevertex.JPG (49996 bytes) bombimmaleside.JPG (41127 bytes) bombimmalescutum.JPG (54150 bytes) bombimmaleterga.JPG (47426 bytes) bombimmaleterga3_6.JPG (45617 bytes) 

bombimmalewing.JPG (52145 bytes) bombimmalegenitalia.JPG (39867 bytes) bombimmalegenitalia2.JPG (40140 bytes) bombimmalegenitaliaside.JPG (43994 bytes) 


Subgenus Pyrobombus, species group Cullumanobombus Vogt.; 2 taxa

Apidae: Bombus fraternus Smith

County Records: Alachua, Gadsden, Levy, Liberty, Orange, St. John, Volusia

bomfra.jpg (71053 bytes)

Locations: Altamonte, Glen St. Mary, Orlando (add counties), Gainesville, Vilano Beach, Wewahitchka,

Dates: Queens: April; Workers: June-August; Males August-October

Plants: polylectic

Notes: This species might be limited to the panhandle and northern peninsula based on the map above.



bomfraqueenface.JPG (63179 bytes) bomfraqueenclypeus.JPG (67789 bytes) bomfraqueenlabrum.JPG (74195 bytes) bomfraqueenmalarspace.JPG (61943 bytes) bomfraqueenocelli.JPG (61695 bytes)

bomfraqueenocelli2.JPG (56295 bytes) bomfraqueenvertextop.JPG (44041 bytes) bomfraqueenwingbroad.JPG (46645 bytes) bomfraqueenwing.JPG (57132 bytes) bomfraqueentop.JPG (45660 bytes)

bomfraqueenside.JPG (41828 bytes) bomfraqueenscutum.JPG (38327 bytes) bomfraqueenscutellum.JPG (54243 bytes) bomfraqueenpropodeum.JPG (55406 bytes) bomfraqueenterga.JPG (43043 bytes)

bomfraqueenterga1corner.JPG (43195 bytes) bomfraqueenterga3-6.JPG (58715 bytes) bomfraqueentergalast.JPG (56311 bytes) bomfraqueenscopa.JPG (62780 bytes) 


bomfraworkerface2.JPG (36232 bytes) bomfraworkerface.JPG (51202 bytes) bomfraworkerclypeus.JPG (46589 bytes) bomfraworkermandible.JPG (48957 bytes) bomfraworkermalarspace.JPG (56528 bytes)

bomfraworkerocelli.JPG (53121 bytes) bomfraworkervertex.JPG (45418 bytes) bomfraworkervertex2.JPG (47429 bytes) bomfraworkertop.JPG (44890 bytes) bomfraworkerwing.JPG (37466 bytes)

bomfraworkerside.JPG (42213 bytes) bomfraworkerside2.JPG (34568 bytes) bomfraworkerterga.JPG (44485 bytes) bomfraworkerterga1&2.JPG (57137 bytes) bomfraworkercorbicula.JPG (53984 bytes)


bomframaleface.JPG (48004 bytes) bomframalecheek.JPG (41710 bytes) bomframalemalarspace.JPG (54728 bytes) bomframaleocelli.JPG (58575 bytes) bomframalevertex.JPG (60876 bytes)

bomframaletop.JPG (40806 bytes) bomframaleside.JPG (45066 bytes) bomframaleside2.JPG (35369 bytes) bomframalescutum.JPG (40653 bytes) bomframalescutumclose.JPG (55470 bytes)

bomframalescutellum.JPG (54398 bytes) bomframaleterga.JPG (42024 bytes) bomframaleterga1&2.JPG (50094 bytes) bomframalelasttergum.JPG (40753 bytes) bomframalegenitalia.JPG (43719 bytes)

bomframalegenitalia2.JPG (39791 bytes) bomframalegenitaliaside.JPG (36486 bytes) bomframalegenitaliaside2.JPG (36747 bytes) 



Apidae: Bombus griseocollis De G.

County Records: Alachua, Broward, Highlands

bomgri.jpg (71396 bytes)

Locations: Lake Placid. Everglades, Palatka, Pinecrest

Dates: March-October; Queens: November, April; Workers: April-June; Males: April in Florida; this species may be active during the winter months in southern Florida.

Plants: polylectic

Notes: Probably occurs throughout Florida but never in great numbers.



bomgriqueenfront.JPG (50034 bytes) bomgriqueenclypeus.JPG (59614 bytes) bomgriqueencheek.JPG (54809 bytes) bomgriqueenmandibles.JPG (56354 bytes) bomgriqueenmalarspace.JPG (50521 bytes)

bomgriqueenocelli.JPG (44898 bytes) bomgriqueenocelliclose.JPG (58921 bytes) bomgriqueenvertex.JPG (48113 bytes) bomgriqueenvertexside.JPG (35430 bytes) bomgriqueenwing.JPG (41647 bytes)

bomgriqueenwing2.JPG (45813 bytes) bomgriqueenscutum.JPG (46933 bytes) bomgriqueenscutum2.JPG (57018 bytes) bomgriqueenscutumclose.JPG (58599 bytes) bomgriqueenscutellum.JPG (59648 bytes)

bomgriqueenside.JPG (40884 bytes) bomgriqueenterga.JPG (60523 bytes) bomgriqueenterga2.JPG (46868 bytes) bomgriqueenterga1&2.JPG (53463 bytes) bomgriqueenterga1&2_2.JPG (52049 bytes)


bomgriworkerface.JPG (56578 bytes) bomgriworkermandible.JPG (60874 bytes) bomgriworkermalarspace.JPG (78165 bytes) bomgriworkerocelli.JPG (60350 bytes)


bomgrimalefront.JPG (34121 bytes) bomgrimaleface.JPG (45127 bytes) bomgrimalelabrum.JPG (50910 bytes) bomgrimalecheek.JPG (44704 bytes) bomgrimalemalarspace.JPG (52042 bytes) 

bomgrimaleocelli.JPG (60587 bytes) bomgrimalevertexside.JPG (44279 bytes) bomgrimaleside.JPG (44916 bytes) bomgrimalescutum.JPG (47025 bytes) bomgrimaleterga.JPG (51543 bytes)

bomgrimaleterga1&2.JPG (57558 bytes)  bomgrimaletergarear.JPG (55322 bytes) bomgrimalegenitaliadorsalclose.JPG (52510 bytes) bomgrimalegenitaliaside.JPG (45616 bytes) bomgrimalegenitaliaventral.JPG (32145 bytes)


Subgenus Psithyrus, one taxon

Apidae: Bombus variabilis Cresson

County Records: Leon, Miami-Dade

bomvar.jpg (70832 bytes)


Dates: In Miami-Dade County, specimens were collected January-April, and then again in November and December. In Leon County, all specimens were collected in October.

Plants: polylectic, forages solely for nectar

Notes: probably throughout the state although collections are only known from Miami-Dade and Leon; Parasite on Bombus species.

Female and male and comparison with Bombus pensylvanicus:

psivar.jpg (91556 bytes) psythrus2.jpg (241152 bytes) 


bomvarmalecheek.JPG (49098 bytes) bomvarmalemalarsp.JPG (61675 bytes) bomvarmaleside.JPG (45529 bytes) bomvarmalevertex.JPG (51819 bytes) bomvarmalevertex2.JPG (55145 bytes) bomvarmaletop.JPG (50837 bytes) bomvarmalescutum.JPG (56925 bytes) bomvarmalescutellum.JPG (61516 bytes) bomvarmalesidepleura.JPG (52789 bytes)

 bomvarmalewing.JPG (31372 bytes) bomvarmaleterga.JPG (53304 bytes) bomvarmaleterga2.JPG (48708 bytes) bomvarmaleterga3.JPG (49560 bytes) bomvarmalegenitalia.JPG (46584 bytes)

bomvarmalegenitalia2.JPG (43346 bytes) bomvarmalegenitalia3.JPG (35248 bytes) bomvarmalegenitalia4.JPG (38301 bytes) bomvarmalegenitalia5.JPG (39752 bytes) bomvarmalegenitalia6.JPG (48139 bytes)

bomvarmalegenitalia7.JPG (34980 bytes) bomvarmalegenitalia8.JPG (44387 bytes) bomvarmalegenitalia9.JPG (38829 bytes)