Lasioglossum (Dialictus) hartii (Robertson)

(Figures 126–130)

Halictus hartii Robertson, 1892: 268 . Ƥ.

Holotype. Ƥ USA, Illinois [INHS: Hart #17211]. Lost (Webb 1980). Halictus rugosus Crawford, 1902a: 237 . Ƥ 3.

Holotype. Ƥ USA, Nebraska, Nebraska City,, 12.ix.1901, on Solidago (M.A. Carriker); [NMNH: 8233]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) hartii, p. 1114 (catalogue); Mitchell, 1960: Dialictus hartii Ƥ3, p. 396 (redescription); Krombein, 1967: Lasioglossum (Dialictus) hartii, p. 463 (catalogue); Moure and Hurd, 1987: Dialictus hartii, p. 102 (catalogue).

Diagnosis. Both sexes of L. hartii can be recognised by the following diagnostic combination: mesoscutum coarsely rugose, punctures distinct only medially (Figs. 127, 129) and pronotal ridge carinate. Male L. hartii often can be further distinguished by gena with strong tubercle and mandible elongate, extending to opposing mandibular base (Fig. 128 B).

Redescription. FEMALE. Length 6.05–6.29 mm; head length 1.58–1.85 mm; head width 1.82–2.03 mm; forewing length 4.30–4.66 mm.

Colouration. Head and mesosoma blue, with greenish reflections. Clypeus with apical half blackish brown, basal half and supraclypeal area bronze. Antenna blackish brown, flagellum with ventral surface dark reddish brown. Tegula dark reddish brown. Wing membrane faintly dusky, venation and pterostigma amber. Legs brown, except tarsi reddish brown. Metasoma blackish brown, terga and sterna with apical margins reddish.

Pubescence. Dull to yellowish white. Relatively sparse. 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 with sparse subappressed hairs. Gena without tomentum. Propodeum with dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with sparse, fine hairs. T1 acarinarial fan with dorsal opening. T2–T3 with at most sparse tomentum basolaterally. T2 apicolateral and T3–T4 apical margins without fringes.

Surface sculpture. Face weakly imbricate, punctation coarse. Clypeus polished, basal margin imbricate, punctation dense (i≤d). Supraclypeal area with punctation dense (i≤d). Lower paraocular with punctation moderately dense (i≤d). Antennocular area reticulate. Upper paraocular area and frons rugulose. Ocellocular area polished, finely punctate (i=1–1.5d). Gena carinulate and postgena imbricate. Mesoscutum coarsely rugose imbricate, punctation separated only medially (i≤d). Mesoscutellum similar to mesoscutum, submedial punctation moderately dense (i=1–1.5d). Axilla punctate. Metanotum rugulose. Preëpisternum, hypoepimeral area, mesepisternum, and metepisternum strongly rugose. Metapostnotum rugoso-carinulate with broad polished areas between rugae. Propodeum strongly rugose, except posterior surface rugulose-imbricate. Metasomal terga polished except marginal areas faintly coriarious, punctation very fine dense (i=1.5–2.5d), apical margins narrowly impunctate.

Structure. Head very wide (length/width ratio = 0.87–0.89). Eyes weakly convergent below (UOD/LOD ratio = 1.09–1.15). Clypeus 2/3 below suborbital line, apicolateral margins convergent. Supraclypeal area strongly protuberant. Antennal sockets close (IAD/OAD <0.6). Frontal line carinate, ending <2 OD below median ocellus. Gena narrower than eye. Pronotal ridge carinate, interrupted by oblique sulcus. Inner metatibial spur pectinate with 3–4 branches. Metapostnotum posterior margin sharply angled, nearly carinate. Metapostnotum moderately truncate (MMR ratio = 1.31–1.43), posterior margin carinate. Propodeum with oblique carina very strong, lateral carina strong reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length. 5.63–6.11 mm; head length 1.44–1.70 mm; head width 1.61–1.92 mm; forewing length 3.81–4.36 mm.

Colouration. Mandible yellow. Flagellomere with ventral surface orange-yellow. Legs brown, except tarsi yellowish brown.

Pubescence. Lower paraocular area with dense tomentum. Face below antennal sockets otherwise with sparse subappressed tomentum, partially obscuring surface. S4 apicolateral and S4 lateral portions with posteriorly directed tufts (i=1.5–2 OD).

Surface sculpture. Mesoscutal punctures more distinct between parapsidal lines (i=1–1.5d).

Structure. Head wide (length/width ratio = 0.89–90). Eyes weakly convergent below (UOD/LOD ratio = 1.07–1.17). Mandible elongate, nearly reaching opposing mandible base. Clypeus 1/2 below suborbital line, apicolateral margins subparallel. Antennal sockets distant (IAD/OAD> 1.0). Frontal line carinate, ending 1.5 OD below median ocellus. Pedicel shorter than F1. F2 length 1.4–1.7X F1. F2–F10 elongate (length/width ratio = 1.57–1.64). Gena often with large triangular tubercle. Pronotal dorsolateral angles acute. Pronotal ridge carinate, uninterrupted. Metapostnotum moderately truncate (MMR ratio = 1.27–1.35), posterior margin sharply angled onto posterior surface. Propodeum with less evident oblique and lateral carinae.

Terminalia . S7 with median lobe very narrow, acuminate (Fig. 130). S8 with apicomedial margin strongly convex (Fig. 130). Genital capsule as shown in Fig. 130. Gonobase with ventral arms narrowly separated. Volsella roughly ovoid. Gonostylus elongate, dorsal setae elongate. Retrorse lobe elongate, attenuated apically.

Range. Minnesota, south to Alabama, Texas (Fig. 82). USA: AL, AR, IL, LA, MI, MN, MO, NC, TX.

Additional material examined. USA: ALABAMA: 1Ƥ Decatur, viii.1944 (G.E. Bohart) [BBSL]; ARKANSAS: 1Ƥ Clinton Co., 10 mi NE Dewitt, 27.viii.1967 (D.P. Gregory); [CUIC]; IOWA: 1Ƥ Louisa Co., Columbus Junction; [CUIC]; LOUSIANA: 2ƤƤ Tallulah, iv. [NMNH]; MICHIGAN: 1Ƥ Saginaw Co., N43.34275 W84.10839, 25.vi.2009, (Tuell et al.); [PCYU]; MINNESOTA: 1Ƥ Houston Co., 21.v.1938 (P. Nicholson); [NCSU]; MISSOURI: 1Ƥ Lincoln Co., NE Elseberry on Mississippi, 26.viii.2001 (Arduser); 1Ƥ Perniscot Co., 4 mi S of Portageville, 25.ix.2004 (Arduser); [PCYU]; NEBRASKA: 1Ƥ ( H. rugosus paratype) Nebraska City, 19.v.1901 (M.A. Carriker); 13 ( H. rugosus paratype) Nebraska City, 12.ix.1901 (M.A. Carriker); [NMNH]; NORTH CAROLINA: 2ƤƤ13 Hyde Co., 28.v.1957 (T.B. Mitchell); [CUIC]; 1Ƥ13 Hyde Co., 27.v.1957 (T.B. Mitchell); 1Ƥ2433 Hyde Co., 28.v.1957 (T.B. Mitchell); [NCSU]; TEXAS: 1Ƥ233 Liberty, 22.vi.1917 (C.U. Expedit.); [CUIC].

Floral records. ASTERACEAE: Anthemis, Erigeron, Solidago, Vernonia; BRASSICACEAE: Capsella, Rorippa; CLUSIACEAE: Hypericum; FABAEAE: Vicia; ONAGRACEAE: Gaura longiflora; ROSACEAE: Rubus .

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon. Lasioglossum hartii is widely distributed in the eastern United States but uncommonly collected. This species has a preference for wetland areas (M. Arduser, in litt.).