Tribe Anthidini

Genus Stelis Panzer, 5 taxa

This is a genus of parasitic Megachilidae that parasitize other Megachilinae. Three subgenera, Dolichostelis Parker and Hurd, Protostelis Friese, and Stelis Panzer, are found in Florida. Michener (2001) considers all of these to be subgenera of the larger genus Stelis.

Keys to the subgenera (from Michener 2000)

For both males and females

  1. Hind tibia with a single prominent tooth or tibial spine (usually hidden among hairs) on margin near apex of posterior margin of tibia; hind basitarsus with strong lamella-like carina along posterior margin, separated by longitudinal depression from longitudinal thickening of outer surface of basitarsus…S. (Protostelis)
  2. Hind tibia with an apical median tooth or tibial spine and a less prominent, rounded projection near apex of posterior margin of tibia; hind basitarsus unmodified…2

  3. Base of propodeum with zone set off by carina and divided into a series of pits, this zone projecting subhorizontally behind vertical metanotum; anterior surface of mesepisternum impunctate at least below and set off from lateral surface by sharp angle or weak omualar carina…S. (Dolichostelis)

Base of propodeum vertical or sloping, rarely subhorizontal, without series of pits or such pits usually present only laterally, this zone with about same slope as metanotum; anterior surface of mesepisternum puncate, omaular carina absent…S. (Stelis s. str)

Dolichostelis Parker and Hurd, 1 species

(Mitchell placed these in Stelis). These are cleptoparasites in nests of Megachile (Chelostomoides)

Megachilidae: Stelis louisae Cockerell (= S. floridana Graenicher, = S. costalis Mitchell (misidentification), and S. costalis Krombein (misidentification)

County Records: Alachua, Hardee, Highlands, Levy, Manatee, Marion, Miami-Dade, Santa Rosa

stelou.jpg (72761 bytes)

Locations: Bowling Green, Brandon

Dates:

Plants:

Notes: This species has a tortured history of misidentifications. For details, see Parker, F. D. and G. E. Bohart. 1979. Dolichostelis, a new genus of Parasitic Bees (Hymenoptera: Megachilidae). Journal of the Kansas Entomological Society 52(1): 138-153. The taxa called S. floridana is a form that has more extensive and darker red-orange markings than populations further to the north but there are intermediates. Their map shows it occuring throughout the peninsula but absent from the panhandle west of probably Lake City?.

Female: steloufemface.JPG (55341 bytes) steloufemmandiblefront.JPG (74260 bytes) steloufemvertex.JPG (71562 bytes) steloufemwing.JPG (41419 bytes) steloufemtop.JPG (53433 bytes) steloufemscutum.JPG (71216 bytes) steloufemscutellum.JPG (71695 bytes) steloufempropodealpits.JPG (64347 bytes) steloufemtergatop.JPG (74765 bytes) steloufemtergatop2.JPG (61687 bytes) steloufemterga3_6.JPG (47403 bytes) steloufembelow.JPG (55046 bytes) steloufemtibiabasitarsus.JPG (48978 bytes) steloufemtibiabasitarsus2.JPG (49313 bytes) steloufemside.JPG (45961 bytes) steloufemside2.JPG (50117 bytes) steloufemmesepisternumside.JPG (66714 bytes) steloufemmesepisternumsidefront.JPG (51386 bytes)

Male: steloumalefront.JPG (41915 bytes) steloumaleface.JPG (48711 bytes) steloumaleclypeus.JPG (72358 bytes) steloumalemandiblefront.JPG (51335 bytes) steloumalemandiblefront2.JPG (42954 bytes) steloumalevertextop.JPG (71298 bytes) steloumalewing.JPG (36723 bytes) steloumaletop.JPG (51333 bytes) steloumalescutum.JPG (76158 bytes) steloumaletegulae.JPG (64213 bytes) steloumalescutellum.JPG (64739 bytes) steloumalepropodealpits.JPG (54108 bytes) steloumaletergatop.JPG (51888 bytes) steloumaleterga1_3.JPG (65775 bytes) steloumaleterga3_6.JPG (44685 bytes) steloumaleterga6.JPG (51912 bytes) steloumaletergaside.JPG (49590 bytes) steloumaletergaside2.JPG (51960 bytes) steloumalemesepisternumside.JPG (50795 bytes) steloumalegenitaldorsal.JPG (39804 bytes) steloumalegenitalside.JPG (46812 bytes) steloumalegenitalventral.JPG (44399 bytes) 

 

Subgenus Protostelis Friese, 3 species

(Mitchell and Hurd incorrectly placed these in Heterostelis). These are likely parasites of the genus Trachusa.

Key to females of Stelis, subgenus Protostelis

  1. Larger (13mm); mandibles more elongate, 2nd tooth being midway between apex and inner angle; tergum 6 obtusely angulate on each side..S. grossa
  2. Smaller (10mm); mandibles shorter, 2nd tooth much nearer apex than to inner angle; tergum 6 regularly rounded…2

  3. Abdominal terga 1 and 2 broadly ferruginous medially, between the yellow lateral maculations..S. australis floridensis

Terga 1 and 2 black medially…S. australis australis

 

Males have not been described for S. grossa

 

 

Megachilidae: Stelis australis australis Cresson

County Records: Alachua, Levy, Putnam, Volusia

steausaus.jpg (74033 bytes)

Locations: Cassadega

Dates: May (1), August (1)

Plants:

Notes: Thorp (1966) listed it for Florida from Volusia county.

 

Megachilidae: Stelis australis floridensis Mitchell

County Records: Alachua, Citrus, Clay, Levy

steausflo.jpg (74350 bytes)

Locations: Inverness

Dates: May-August

Plants:

Notes: This subspecies appears to be restricted to Florida. These two subspecies may represent nothing more a color cline according to Thorp (1966) but they have been found together. Possibly, coloration is dependent on local environmental conditions that affect the nesting larvae.

Male: steausflomalefront.JPG (40778 bytes) steausflomaleface.JPG (65580 bytes) steausflomalemandiblefront.JPG (59044 bytes) steausflomalemandible.JPG (57555 bytes) steausflomalevertextop.JPG (70838 bytes) steausflomalevertextop2.JPG (74624 bytes) steausflomalewing.JPG (43336 bytes) steausflomaletop.JPG (55012 bytes) steausflomalescutum.JPG (84362 bytes) steausflomaletubercle.JPG (62702 bytes) steausflomaletegulae.JPG (84483 bytes) steausflomalescutellum.JPG (74405 bytes) steausflomalescutellumoblique.JPG (63287 bytes) steausflomaletergatop.JPG (55800 bytes) steausflomaleterga3_6.JPG (60504 bytes) steausflomaleside.JPG (52517 bytes) steausflomalefaceside.JPG (62687 bytes) steausflomalemesepisternumside.JPG (66381 bytes) steausflomalemesepisternumcarinaside.JPG (61356 bytes) steausflomalebelow.JPG (48499 bytes) steausflomalebasitarsusgroove.JPG (49686 bytes) steausflomalebasitarsusgrooveclose.JPG (51930 bytes) steausflomaletibialspur.JPG (46259 bytes) steausflomalesterna.JPG (75175 bytes) steausflomalesternalast.JPG (51691 bytes) 

 

Megachilidae: Stelis grossa Mitchell

County Records: Alachua

stegro.jpg (71992 bytes)

Locations:

Dates: October

Plants:

Notes: Was described from Florida, Thorp (1966) and Hurd (1979) lists it also from Ft. Morgan, Alabama (Baldwin County). Probably occurs in north-central peninsula and in the panhandle. Photos are not yet available.

 

Subgenus Stelis Panzer, 1 species

 

Megachilidae: Stelis ater Mitchell

County Records: Collier, Sarasota

steate.jpg (71888 bytes)

Locations: Corkscrew Swamp

Dates: January, March

Plants:

Notes: Endemic to Florida, known only from the southwestern coastal region. Photos are not yet available.