Lasioglossum (Dialictus) tamiamense (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 188-191

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Lasioglossum (Dialictus) tamiamense (Mitchell)


Lasioglossum (Dialictus) tamiamense (Mitchell)

( Figures 204–206 View FIGURE 204 View FIGURE 205 View FIGURE 206 )

Dialictus tamiamensis Mitchell, 1960: 421 . Ƥ 3.

Holotype. Ƥ USA, Florida, Olga, 29.iii. 1954, on sand flats (K.V. Krombein); [ NMNH: 66070]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) tamiamense , p. 466 (catalogue); Moure and Hurd, 1987: Dialictus tamiamensis , p. 133 (catalogue).

Diagnosis. Female L. tamiamense can be recognised by the following diagnostic combination: head long (length/ width ratio = 1.08–1.09) ( Fig. 204 View FIGURE 204 B); mesoscutal punctures dense, except along medial line ( Fig. 205 View FIGURE 205 ); metapostnotal rugae very fine, obscure among tessellate background ( Fig. 205 View FIGURE 205 ); T 1 acarinarial fan large, complete ( Fig. 205 View FIGURE 205 ), intermixed with erect hairs dorsally; and T 2 apical impressed area with distinct but fine punctation. They are most similar to L. halophitum and L. creberrimum . Female L. halophitum have mesoscutal punctures sparse over most of disc only becoming dense adjacent to the parapsidal lines ( Fig. 122 View FIGURE 122 ). Female L. creberrimum have T 1 acarinarial fan smaller without intermixed erect hairs dorsally, and T 2 apical impressed area with very obscure punctation.

Male L. tamiamense can be recognised by the following diagnostic combination: head long (length/width ratio = 1.07) ( Fig. 206 View FIGURE 206 B), clypeus with distal margin brownish yellow ( Fig. 206 View FIGURE 206 B), mesoscutal punctures contiguous (i<d), T 1 – T 2 apical impressed areas impunctate, and S 5 apical margin deeply concave with dense apicolateral hairs. They are most similar to male L. creberrimum , which have T 1 –T 2 at most narrowly impunctate at apical margin and S 5 apical margin weakly concave with sparse apicolateral hairs.

Redescription. FEMALE. Length 4.60–5.02 mm; head length 1.52–1.54 mm; head width 1.40–1.42 mm; forewing length 3.39–3.45 mm.

Colouration. Head and mesosoma blue with greenish reflections. Clypeus with apical half blackish brown. Supraclypeal area bronze. Antenna dark brown, flagellum with ventral surface reddish brown. Tegula brownish yellow. Wings faintly dusky, venation and pterostigma brownish yellow. Legs brown, except medio- and distitarsi reddish brown. Metasomal terga and sterna brown, apical margins translucent brownish yellow.

Pubescence. Dull white. Head and mesosoma with moderately dense woolly hairs (1–1.5 OD), longest on genal beard, metanotum, and mesopleuron (2–2.5 OD). Paraocular area and gena without subappressed tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with moderately dense, fine hairs. T 1 acarinarial fan complete. T 2 –T 5 lateral portions with sparse tomentum. T 2 apicolateral and T 3 –T 4 apical margins with sparse fringes.

Surface sculpture. Face imbricate, punctation fine. Clypeus punctation dense (i≤d). Supraclypeal area with punctation moderately dense (i≤d). Lower paraocular and antennocular areas with punctation dense (i≤d). Upper paraocular area, frons and ocellocular area punctate-reticulate. Gena and postgena lineolate. Mesoscutum tessellate, punctation fine, dense on medial portion of disc (i= 1–1.5 d), punctate-reticulate mesad and laterad of parapsidal line and on anterolateral portion. Mesoscutellum weakly imbricate-tessellate, submedial punctation moderately dense (i<d). Axilla punctate. Metanotum imbricate. Preëpisternum rugose. Hypoepimeral area imbricate. Mesepisternum rugose, rugulose posteriorly. Metepisternum with dorsal half rugoso-carinulate, ventral half imbricate. Metapostnotum with very weak rugae, posterior margin tessellate-granular. Propodeum with dorsolateral slope carinulate, lateral surface imbricate-tessellate, posterior surface tessellate. Metasomal terga polished, punctation moderately dense throughout (i= 1–1.5 d), sparser on apical impressed areas (i= 1–2.5 d).

Structure. Head elongate (length/width ratio = 1.08–1.09). Eyes convergent below (UOD/LOD ratio = 1.23–1.26). Clypeus ½ below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2.5 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 3–4 branches. Metapostnotum truncate (MMR ratio = 1.30–1.35), posterior margin narrowly rounded onto posterior surface. Propodeum with oblique carina fine, lateral carina weak, reaching halfway to dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 3.81 mm; head length 1.39 mm; head width 1.30 mm; forewing length 2.96 mm.

Colouration. Labrum, mandible and distal margin of clypeus yellow. Flagellum with ventral surface brownish yellow. Legs brown, except tibial bases and apices and tarsi brownish yellow.

Pubescence. Paraocular area below eye emargination with tomentum obscuring surface. Clypeus largely obscured by tomentum. S 2 –S 3 with posteriorly directed hairs (1–1.5 OD), S 4 –S 5 apical margins with dense hairs.

Surface sculpture. Mesoscutellar punctation dense (i<d). Metasomal terga with apical impressed areas impunctate.

Structure. Head elongate (length/width ratio = 1.07). Eyes strongly convergent below (UOD/LOD ratio = 1.38). Clypeus 2 / 3 below suborbital tangent, apicolateral margins subparallel. Antennal sockets distant (IAD/OAD> 0.7). Frontal line carinate, ending 2 OD below median ocellus. Pedicel shorter than F 1. F 2 length 1.8 X F 1. F 2 –F 10 moderately elongate (length/width ratio = 1.50–1.60). Metapostnotum elongate (MMR ratio = 1.28), posterior margin rounded onto posterior surface. S 5 deeply concave.

Terminalia . S 7 with median lobe acuminate. S 8 with apicomedial margin weakly convex. Gonobase with ventral arms separated. Volsella roughly ovoid. Gonostylus long, dorsal setae elongate. Retrorse lobe elongate, attenuated apically.

Range. Florida ( Fig. 199 View FIGURE 199 ).

Additional material examined. USA: FLORIDA: 1 Ƥ Highlands Co., Archbold Biological Station, N 27.18833 W081.33778, 18.iii. 2002 (J.S. Ascher); 13 Putnam Co., Crescent City, N 29.43 W081.5108, 20.iv. 1908 (Van Duzee); [ AMNH];; 1 Ƥ paratype Punta Gorda, 11.iv. 1962 (J.R. Vockeroth); [ CNC]; 2 ƤƤ paratypes East end Tamiami Trail, 1949 (T.B. Mitchell); 6 ƤƤ paratype Marion Co., 8.iv. 1956 (R.A. Morse); 13 Punta Gorda, 17.xi. 1911; 1 Ƥ Highlands Co., Archbold Bio. Res. Stn., 14.iv. 1963 (J.G. & B.L. Rozen); 13 Highlands Co., Highland Hammock S.P., 13.iv. 1974 (G.C. Eickwort); 1 Ƥ Alachua Co., 13.ii. 1930 (C.J. Guard); 13 Columbia Co., 22.i. 1930 (R.B. Howard); 1 Ƥ Orange Co., 7–15.ii. 1930 (W.M. Loe)); 1 Ƥ Volusia Co., 29.i. 1930 (W.A. Hiers); 1 Ƥ Union, Walton Co., 23.xii. 1929 (R.B. Howard); [ CUIC]; 1 Ƥ ( Halictus ashmeadi paratype) Inverness (C. Robertson); [ INHS]; 4 ƤƤ paratypes East end Tamiami Trail, 1949 (T.B. Mitchell); 4 ƤƤ paratypes Marion Co., 6.iv. 1956 (R.A. Morse); 2 ƤƤ paratypes Marion Co., 17.iv. 1956 (R.A. Morse); 1 Ƥ paratype Olga, 29.iii. 1954 (K.V. Krombein); 13 paratype Olga, 30.iii. 1954 (K.V. Krombein); 2 ƤƤ paratypes Volusia Co., 10.viii. 1936 (H.A. Denmark); [ NCSU]; 13 paratype Olga, on sand flats, 30.iii. 1954 (K.V. Krombein); [ NMNH].

Floral records. ASTERACEAE : Bidens pilosa , Erigeron quercifolius ; FABACEAE : Chamaecrista fasciculata , Medicago “lupina”, Melilotus officinalis , Trifolium repens ; HYDROPHYLLACEAE : Hydrolea ovata ; LAMIACEAE : Stachys floridana .

DNA Barcode. Available. Single sequence.

Comments. Uncommon.

Several paratypes of L. tamiamense are in fact L. creberrimum (one paratype from Alachua county is a L. puteulanum ).


Smithsonian Institution, National Museum of Natural History


American Museum of Natural History


Canadian National Collection of Insects, Arachnids, and Nematodes


Cornell University Insect Collection


Illinois Natural History Survey


North Carolina State University Insect Museum


Department of Natural Resources, Environment, The Arts and Sport














Lasioglossum (Dialictus) tamiamense (Mitchell)

Gibbs, Jason 2011

Dialictus tamiamensis

Mitchell 1960: 421