Lasioglossum (Dialictus) halophitum (Graenicher)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 109-112

Lasioglossum (Dialictus) halophitum (Graenicher)

( Figures 121–125 )

Halictus (Chloralictus) halophitus Graenicher, 1927: 206 . Ƥ 3.

Holotype. Ƥ USA, Florida, Cutler, south of Miami, 5.v.1923 (S. Graenicher); [ NMNH]. Examined. Halictus halophilus Graenicher, 1930: 156 . (Emend.)

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) halophitum , p. 1113 (catalogue); Mitchell, 1960: Dialictus halophitus , p. (redescription); Krombein, 1967: Lasioglossum (Dialictus) halophitum , p. 463 (catalogue); Moure and Hurd, 1987: Dialictus halophitus , p. 102 (catalogue).

Diagnosis. Female L. halophitum can be recognised by the following diagnostic combination: head elongate (length/ width ratio = 1.06–1.08) ( Fig. 121 B); mesoscutal punctures sparse between parapsidal lines ( Fig. 122 ); metapostnotal rugae very fine, medially obscure among tessellate background ( Fig. 122 ).They are most similar to L. creberrimum and L. tamiamense , which both have dense mesoscutal punctures.

Male L. halophitum can be recognised by the following diagnostic combination: head elongate (length/width ratio = 1.09–1.12) ( Fig. 123 B); eyes weakly convergent below ( Fig. 123 B), mesoscutal punctures sparse between parapsidal lines ( Fig. 124 ), and metapostnotal rugae fine. They are most similar to male L. creberrimum and L. tamiamense , which both have dense mesoscutal punctures.

Redescription. FEMALE. Length 5.14–5.75 mm; head length 1.58–1.85 mm; head width 1.49–1.70 mm; forewing length 3.63–4.24 mm.

Colouration. Head and mesosoma pale green to bluish green. Clypeus with apical half blackish brown. Supraclypeal area bronze. Antenna dark brown, flagellum with ventral surface brownish orange. Tegula reddish to brown. Wings faintly dusky, venation and pterostigma yellowish brown. Legs brown, except medio- and distitarsi reddish brown. Metasomal terga and sterna brown, apical margins pale, translucent 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 with sparse subappressed tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with moderately dense, fine hairs. T1 acarinarial fan sparse, interspersed with erect hairs, incomplete due to large dorsal opening. T2–T3 laterally and T4–T5 with sparse tomentum not obscuring surface. T2–T4 apical margins with moderately sparse fringes.

Surface sculpture. Face imbricate, punctation fine. Clypeus punctation (i=1–2.5d). Supraclypeal area with punctation moderately dense (i=1–1.5d). Lower paraocular and antennocular areas with punctation dense (i≤d). Upper paraocular area and frons punctate-reticulate. Ocellocular area punctate (i≤d). Gena and postgena lineolate. Mesoscutum imbricate, punctation sparse on most of disc (i=1–3d), densely punctate mesad and laterad of parapsidal line and on anterolateral portion (i≤d). Mesoscutellum weakly imbricate, submedial punctation very sparse (i=1–6d). Axilla punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area rugulose-imbricate. Mesepisternum rugulose. Metepisternum with dorsal half rugoso-carinulate, ventral half imbricate. Metapostnotum weakly rugoso-carinulate, posterior margin tessellate-imbricate. Propodeum with dorsolateral slope carinulate, lateral surface ruguloso-imbricate, posterior surface tessellate. Metasomal terga weakly coriarious, punctation moderately dense throughout (i=1–1.5d).

Structure. Head elongate (length/width ratio = 1.06–1.08). Eyes convergent below (UOD/LOD ratio = 1.18–1.26). Clypeus ½ below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 3– 5 branches. Metapostnotum truncate (MMR ratio = 1.45–1.47), posterior margin weakly rounded onto posterior surface. Propodeum with oblique carina fine, lateral carina weak, nearly reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.96–5.20 mm; head length 1.67–1.85 mm; head width 1.54–1.66 mm; forewing length 3.63 mm.

Colouration. Labrum and mandible brownish yellow. Flagellum with ventral surface reddish. Legs brown, except tibial bases and apices and tarsi brownish yellow.

Pubescence. Paraocular area below eye emargination with tomentum obscuring surface. S3 and S4 laterally with dense plumose hairs (1–2 OD).

Surface sculpture. Clypeal punctation moderately dense (i=1–2d). Metasomal terga punctation dense except apical impressed areas nearly impunctate, with only a few scattered punctures.

Structure. Head very elongate (length/width ratio = 1.09–1.12). Eyes convergent below (UOD/LOD ratio = 1.22– 1.25). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets distant (IAD/OAD> 0.6). Frontal line carinate, ending 2OD below median ocellus. Pedicel shorter than F1. F2 length 1.5–1.7X F1. F2–F10 moderately elongate (length/width ratio = 1.43–1.67). Metapostnotum short (MMR ratio = 1.52–1.58), posterior margin rounded onto posterior surface.

Terminalia . S7 with median lobe acuminate ( Fig. 125 ). S8 with apicomedial margin weakly convex ( Fig. 125 ). Genital capsule as in Fig. 125 . Gonobase with ventral arms widely separated. Volsella roughly ovoid. Gonostylus elongate, dorsal setae elongate. Retrorse lobe elongate, strongly attenuated apically.

Range. Maryland, south to Caribbean Islands ( Fig. 115 ). BAHAMAS. CUBA. JAMAICA. USA: FL, GA, LA, MD, NC, SC, VA.

Additional specimens examined. BAHAMAS: 1Ƥ San Salvador Island, 18.vi.1978 (N. Elliot); [ CUIC]. JAMAICA: 8ƤƤTrelawny Parish, salt marsh, 9.viii.1985 (G.C. Eickwort); [ CUIC]; USA: FLORIDA: 1Ƥ Tahiti Beach, 22.v.1927 (S. Graenicher); 1Ƥ13 Tahiti Beach, 12.vi.1927 (S. Graenicher); 1Ƥ Tahiti Beach, 28.viii.1927 (S. Graenicher); [ NCSU]; 1Ƥ paratype Cutler, 20.v.1923 (S. Graenicher); 13 paratype Cutler, 20.iv.1923 (S. Graenicher); [ NMNH]; 1Ƥ paratype Cutler, 20.v.1923 (S. Graenicher); 13 paratype Cutler, 20.iv.1923 (S. Graenicher); 13 Dade Co., Everglades N.P., 15.iii.1955 (H.A. Denmark); 1 Ƥ Flamingo, 13.iv.1923; [ CUIC]; 3ƤƤ233 Monroe Co., Knight’s Key, 2.viii.1984 (L. Packer); 1Ƥ Homestead, Miami, 30.viii.2006 (J.A. Genaro); [ PCYU]; GEORGIA: 1Ƥ Bryan Co., Richmond Hill S.P., 2.v.1974 (G.C. Eickwort); 1Ƥ Tybee Island, 26.vii.1913; [ CUIC]; LOUSIANA: 1Ƥ Acadia P., Jct. Hwy 92-Hwy 90, 26.v.1996 (S. Johnson); [ INHS]; MARYLAND: 2ƤƤ Dorchester Co., N38.3814 W076.0677, 21.viii.2003, 2ƤƤ Somerset Co., N37.9 W075.7, 8.v.2002 (S.W. Droege); [ PCYU]; NORTH CAROLINA: 2ƤƤ Hyde Co., N35.4164 W076.1625, 7.vi.2005 (S.W. Droege); [ PCYU]; SOUTH CAROLINA: 13 Georgetown Co., 6 mi. SSW of Murrells Inlet, 28.v.1937 (R. Dow); [ NMNH]; VIRGINIA: 2ƤƤ Assateague I., N37.9576 W075.3147, 30.vi–1.vii.2006 (S.W. Droege); 13 Assateague I., N37.9804 W075.2926, 30.vi–1.vii.2006 (S.W. Droege); 4ƤƤ Assateague I., N37.9124 W075.359, 1– 2.vii.2006 (S.W. Droege); 1Ƥ Accomack Co., N37.9695 W075.3043, 30.vi–1.vii.2006 (S.W. Droege); [ PCYU].

Floral records. AIZOACEAE : Sesuvium maritimum , S. portulacastrum ; AMARANTHACEAE : Achyranthes “mercanthifolia”; ASTERACEAE : Anthemis , Baccharis , Borrichia , Cirsium , Eupatorium , Mikania ; BORAGINACEAE : Heliotropium ; EUPHORBIACEAE : Chamaesyce mesembrianthemifolia , Euphorbia ; PORTULACEAE : Portulaca ; SCROPHULARIACEAE : Bacopa monniera ; SURIANACEAE : Suriana .

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon. Lasioglossum halophitum , as its name suggests, has a preference for salt marshes.

Figures

FIGURE 115. Distribution map of Lasioglossum georgeickworti (stars) and L. halophitum (circles).

FIGURE 121. Lasioglossum halophitum (Graenicher) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 122. Lasioglossum halophitum (Graenicher) female, dorsal view of mesosoma.

FIGURE 123. Lasioglossum halophitum (Graenicher) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 124. Lasioglossum halophitum (Graenicher) male, dorsal view of mesosoma.

FIGURE 125. Lasioglossum halophitum (Graenicher) male terminalia, (A) ventral view, (B) dorsal view. Scale bar = 0.5 mm.