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.

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)

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

2. 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 Graencher, = S. costalis Mitchell (misidentification), and S. costalis Krombein (misidentification)

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

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:

Male:  

Subgenus Protostelis Friese, 3 species

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

1. Larger (13mm); mandibles more elongate, 2^nd tooth being midway between apex and inner angle; tergum 6 obtusely angulate on each side..S. grossa

Smaller (10mm); mandibles shorter, 2^nd tooth much nearer apex than to inner angle; tergum 6 regularly rounded…2

2. 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

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

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:  

Megachilidae: Stelis grossa Mitchell

County Records: Alachua

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

Locations: Corkscrew Swamp

Dates: January, March

Plants:

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