Bouseman and LaBerge (1979) state that "Melandrena are large bees with long malar spaces, tall vertices, and wide genal areas. They usually lack tergal pale fasciae (or these are weak and interrupted) and lack male sternal subapical fimbriae (or these are weak and interrupted). The propodeum usually has the area outside of the dorsal enclosure at least moderately roughened by punctures. The female propodeal corbiculum has simple internal hairs and is incomplete anteriorly and the trochanteral floccus may be complete or incomplete basally."
For more information, see revision by J. K. Bouseman and W. E. LaBerge. 1979. A revision of the bees of the genus Andrena of the Western Hemisphere. Part IX. Subgenus Melandrena. Trans. Amer. Ent. Soc. 104: 275-389.
1. Hind trochanters with flocculus complete...2
Hind trochanters with flocculus incomplete, basal half or more of flocculus composed of short hairs, usually about half as long as hairs near apex...4
2. Terga 2-4 with weak apical pale fasciae at least laterally; labrum apical of process without median crista..A. sayi
Terga 2-4 without trace of pale apical fasciae laterally; labrum with median crista present...3
3. Facial fovea narrow, occupying about one-third of space from inner margin compound eye to outer margin antennal fossa..A. pruni
Facial fovea broader, occupying at least half of space from inner margin compound eye to outer margin antennal fossa..A. barbara
4. Vertex above lateral ocellus equals one ocellar diameter or slightly more...A. confederata
Vertex above lateral ocellus equals one and one-half or two ocellar diameters or slightly more..5
5. Propodeum with dorsal enclosure abruptly declivous posteriorly, usually with one to three short transverse rugulae at apex of dorsal area; pygidial plate broadly rounded apically..A. illini
Propodeum with dorsal enclosure rounded posteriorly, without transverse rugulae; pygidial plate usually pointed or narrowly rounded apically...6
6. Terga 2-4 with weak pale apical fasciae often interrupted medially..A. hilaris
Terga 2-4 without pale apical fasciae..A. obscuripennis
1. Vertex above lateral ocellus equals one ocellar diameter or extremely slightly more; terga dull, evenly shagreened, almost impunctate...A. confederata
Vertex above lateral ocellus equals one and one-half to two ocellar diameters; terga often punctate and often shiny...2
2. Sixth sternum with a tuft of long, plumose, pale hairs hanging downwards, hairs longer than subapical hairs of sternum 5..A. pruni
Sixth sternum with hairs short, often depressed, if hanging downwards near tip of sternum, then half as long as subapical hairs of sternum 5...3
3. Sterna 3-5 with basal areas virtually impunctate, punctures extremely small, obscure, concentrated in a narrow line near base of apical area..A. barbara
Sterna 3-5 with basal areas with distinct punctures scattered over most of surface, concentrated near base of apical areas, punctures distinct...4
4. Propodeum with dorsal enclosure abruptly declivous posteriorly, with one or more short transverse rugulae separating dorsal from posterior surface; terga 2-5 with weak apical fasciae laterally...5
Propodeum with dorsal enclosure evenly rounded posteriorly, without transverse rugulae apically; terga 2-5 often without pale apicolateral fasciae...6
5. Labral process with apical half of less with a row of two to ten distinct punctures; vertex above lateral ocelli equals two to two and one-half ocellar diameters; flagellar segment 1 slightly longer than segment 2...A. illini
Labral process without distinct punctures or only one or two present; vertex above lateral ocellus equals slightly less than two ocellar diameters; flagellar segment 1 usually no longer than segment 2 or shorter...A. sayi
6. Tarsi and hind tibiae bright red to orange, often legs entirely orange except bases of femora, trochanters, or coxae...A. obscuripennis
Tarsi and hind tibiae dark brown to black, at most with distitarsi rufescent..A. hilaris
County Records: Leon
Locations: Known from Tall Timbers Research Station in Leon County. Also collected from Valdosta State University campus and the author's lawn in Valdosta, Georgia. Probably distributed throughout the panhandle. It was not collected during a one year survey of Osceola National Forest and might be limited to higher elevations with sufficient numbers of food plants.
Dates: LaBerge and Bouseman list Feb. 23-May 26 from throughout the range. I have collected it in Valdosta and Leon County Florida from Feb. 27-March 20.
Plant: Polylectic on Rosaceae (Prunus, Crataegus, Pyrus), Salicaceae.
Notes: New State record for Florida. Previously collected in Georgia, Alabama, and Mississippi. This species was confused as A. viburnella Graenicher by Mitchell and with A. perplexa Brimley. This is a large bee common throughout the southeast. The female can be distinguished by the pale scopal hairs, cristate labrum, trapezoidal labral process and distinctly punctate terga. The male has densely and coarsely punctate terga and pale vestiture. This bee nests in lawns and forms large communal nesting areas in the early spring.
County Records: Alachua, Gadsden, Jackson, Suwannee; also found in Thomas and Lowndes Counties, GA.
Locations: Gainesville, Hildreth
Dates: March 22-April 14; March:2, April: 3; Bouseman and LaBerge list Feb-June across the entire range
Plant: Polylectic; Crataegus
Notes: This is a medium sized slender species distinguished from all other North American Melandrena by the short vertex in both sexes. It is believed to be a primitive species of the Melandrena. Probably occurs throughout the panhandle and into the northern peninsula.
County Records: Okaloosa Co., FL (also found in Thomas Co, GA)
Locations: Blackwater River State Forest
Dates: March 10-April 11 (from my collections in Thomas County and the single specimen from Okaloosa County). LaBerge and Bouseman list March 12-July 5 across the entire range, with most specimens taken in April through early June.
Plant: Polylectic, many species.
Notes: Relatively rare bee in collections, new state record for Florida. Previously known from many locations in Georgia. Probably found throughout the Florida panhandle. It resembles pale specimens of A. nivalis, a species not found in Florida. Both sexes have short lateral pale pubescent fasciae on terga 2-4. Females have pale scopal hairs, the labral process lacking both crista and transverse sulcus, incomplete trochanteral floccus, and sparsely punctate and shiny scutellum. Males have a sparsely punctate and shiny scutellum. Both sexes have the galea blade shiny to moderately shiny in the basal half or more.
County Records: Gadsden County (listed in Bouseman and LaBerge)
Locations:
Dates: March 13-June 2 (LaBerge and Bouseman); mostly in April and May across the entire range.
Plant: Polylectic, many species.
Notes: Not found in FSCA collections. Apparently local and rare. Probably limited to the eastern panhandle of Florida. Often confused with Andrena sayi, including in Mitchell. This is a large species that has a incomplete trochanteral floccus, unlike A. sayi that has a complete floccus. Males resemble A. pruni except for the long tuft of hairs on sternum 6. Females also resemble A. hilaris but lack the tergal bands and the rugulose dorsal propodeum. Males have a distinctive punctate apical margin of the labral process.
County Records: Alachua
Locations:
Dates: March 9-April 3, March :2, April:1; Bouseman and LaBerge list April and May for entire range of species
Plant: Crataegus; Bouseman and LaBerge also list Ilex and Batodendron (Vaccinium arboreum)
Notes: New state record for Florida. This species is a species of the coastal plain apparently. It was previously known only from North Carolina. It is a large dark-winged southeastern species related to A. dolomella (known from Texas and Louisiana). The two may be the same species as they are closely related. It is quite distinctive in coloration from the other members of the Melandrena in Florida.
County Records: Leon
Locations: Tall Timbers Research Station
Dates: March 3; Flight dates in literature are April 12-June 28th but these are for northern populations.
Plant: Polylectic according to LaBerge and Bouseman.
Notes: New state record for Florida. The map in LaBerge and Bouseman show the southern limit to be North Carolina with a possible extension into the N. GA mountains. It is rare in collections. Females resemble A. carlini which does not occur in Florida. It has very narrow facial fovea that are distinctive. Males are unique in the large tuft of plumose hairs that hang down on the sixth sternum (see photos below). It is possible that this may be an isolated population, persisting in the eastern panhandle region of Florida. No photos of the female are currently available.
County Records: Gadsden
Locations:
Dates: March 17 in Gadsden. LaBerge and Bouseman report March 2-June 20 across the entire range including many northern locations.
Plant: Data is sparse but appears polylectic; Prunus angustifolia.
Notes: New state record for Florida; previous southern collection was in River Bend, Dougherty County, GA, located to the north of Gadsden County, FL. This is a large conspicuous bee that is rare in collections. It can be distinguished in both sexes by the distinct but interrupted pale tergal bands and the abruptly declivous propodeal dorsal enclosure. The female lacks the labral median crista and the male has a relatively weak beard. It is probably limited to the eastern panhandle region of Florida.
