Lasioglossum (Dialictus) marinum (Crawford)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 140-143

Lasioglossum (Dialictus) marinum (Crawford)

( Figures 155–158 )

Halictus marinus Crawford, 1904: 99 . Ƥ.

Holotype. Ƥ USA, New Jersey, Ocean City, 10.vi.1901; [ ANSP].

Taxonomy. Halictus (Chloralictus) marinus 3 Graenicher, 1927: 203 (description); Halictus (Chloralictus) marinus Graenicher, 1930: 156 (tax. notes). Michener, 1951: Lasioglossum (Chloralictus) marinum , p. 1115 (catalogue); Mitchell, 1960: Dialicutus marinus , p. 404 (redescription, key, lapsus calami ); Krombein, 1967: Lasioglossum (Dialictus) marinum , p. 464 (catalogue); Moure and Hurd, 1987: Dialictus marinus , p. 112 (catalogue).

Diagnosis. Both sexes of L. marinum can be recognised by the following diagnostic combination: tegula enlarged, distinctly punctate with strong posterior angle ( Fig. 156 ), and metasomal terga with metallic reflections.

Description. FEMALE. Length 5.81–6.05 mm; head length 1.74–1.90 mm; head width 1.74–1.80 mm; forewing length 4.17–4.30 mm.

Colouration. Head and mesosoma pale blue with green and golden reflections. Clypeus with apical half blackish brown, basal half, and supraclypeal area bronze. Antenna dark brown, flagellum with ventral surface brownish yelloworange. Tegula dark reddish brown, translucent yellow anteriorly. Wing membrane hyaline, venation and pterostigma pale brownish yellow. Legs brown, except medio- and distitarsi reddish. Metasomal terga faintly metallic green, sterna brown, apical impressed areas amber to pale translucent yellow.

Pubescence. Dull white. Moderately dense. Head and mesosoma with moderately dense woolly hairs (1–1.5 OD), longest on genal beard, metanotum, and mesopleuron (2–2.5 OD). Lower paraocular area, frons and gena with sparse, subappressed tomentum, partially obscuring surface. Metanotum obscured posteriorly by tomentum. Metepisternum obscured by tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with moderately sparse, fine hairs. T1 acarinarial fan dense, complete dorsally. T1 dorsolateral portion with small patch of appressed tomentum. T2 basolaterally, T3 basally and T4–T5 entirely with tomentum. T2 apicolaterally and T3–T4 apically with relatively dense fringes.

Surface sculpture. Face weakly imbricate. Clypeus with apical half polished, punctation irregularly spaced (i=1– 2.5d). Supraclypeal area with punctation dense (i≤d). Lower paraocular area and antennocular area punctation dense (i≤d). Upper paraocular area and frons punctate-reticulate. Ocellocular area minutely punctate (i≤d). Gena and postgena lineolate. Mesoscutum polished, punctation relatively dense on centre of disc (i≤d), sparser posteriorly (i=1–1.5d), contiguous laterad of parapsidal line (i≤d), and subreticulate on anterolateral portion. Mesoscutellum polished, submedial punctation moderately sparse (i=1–2d). Tegula coarsely punctate. Preëpisternum reticulate-punctate. Hypoepimeral area reticulate-punctate. Mesepisternum polished, coarsely punctate anteriorly (i≤d), finely punctate posteriorly. Metepisternum with dorsal half rugoso-carinulate, ventral half imbricate. Metapostnotum rugoso-carinulate. Propodeum dorsolateral slope carinulate, lateral and posterior surfaces imbricate-tessellate. Metasomal terga polished except T1 anterior declivitous surface and apical impressed areas coriarious, punctation on basal halves moderately dense (i=1–1.5d), sparser on apical halves (i=2–3d).

Structure. Head round (length/width ratio = 1.00–1.03). Eyes convergent below (UOD/LOD ratio = 1.20–1.21). Clypeus below 2/3–3/4 suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2 OD below median ocellus. Gena narrower than eye. Tegula elongate with distinct posterior angle. Inner metatibial spur pectinate with 3–4 branches. Metapostnotum truncate (MMR ratio = 1.45–1.56), posterior margin narrowly rounded onto posterior surface. Propodeum with oblique carina very weak, lateral carina weak, not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.02–5.63 mm; head length 1.54–1.56 mm; head width 1.51 mm; forewing length 3.81–3.93 mm.

Colouration. Flagellum with ventral surface orange-yellow. Legs brown, except tarsi brownish yellow.

Pubescence. Face below supraorbital line obscured by dense tomentum. Mesoscutal margins with tomentum. T1–T5 with sparser tomentum. S2–S5 apicolaterally with very sparse plumose hairs (1 OD).

Surface sculpture. Gena polished, postgena lineolate. Mesoscutum punctation sparser between parapsidal lines (i=1– 1.5d). Mesepisternum polished, punctation distinct. Metapostnotum posterior margin imbricate. Propodeum with dorsolateral slope punctate (i≤d), lateral surface ruguloso-imbricate.

Structure. Head elongate (length/width ratio = 1.02–1.03). Eyes convergent below (UOD/LOD ratio = 1.41). Antennal sockets distant (IAD/OAD> 1.2). Pedicel shorter than F1. F2 length 1.5–1.6X F1. F2–F10 moderately short (length/ width ratio = 1.29–1.50). Metapostnotum truncate (MMR ratio = 1.45–1.50), posterior margin rounded onto posterior surface.

Terminalia . S7 with median lobe clavate apex rounded ( Fig. 158 ). S8 with apicomedial margin weakly convex ( Fig. 158 ). Genital capsule as in Fig. 158 . Gonobase with ventral arms broadly separated. Volsella roughly ovoid. Gonostylus small, dorsal setae elongate. Retrorse lobe elongate, roughly parallel sided, weakly attenuated apically.

Range. Coastal sand dunes from Alabama, Florida to Massachusetts ( Fig. 159 ). USA: AL, FL, NC, NJ, NY, VA.

Additional specimens examined. USA: ALABAMA: 1Ƥ13 Baldwin Co., Ft. Morgan S.P., T9S R1E Sec. 1,2, 15.x.1991 (G.C. Eickwort); 13 Baldwin Co., Bon Secour N.W. Ref., T9S R2E Sec. 25 S, 12.x.1991 (G.C. Eickwort); 1Ƥ Miami, 2.i.1925 (S. Graenicher); 1Ƥ 22.x.1927 (S. Graenicher); 1Ƥ golden beach, Miami, 23.iv.1927 (S. Graenicher); [ CUIC]; FLORIDA: 2ƤƤ13 Duval Co., Little Talbot Island S.P., 1.v.1974 (G.C. Eickwort); [ CUIC]; NEW JERSEY: 1Ƥ Ocean Co., Lakehurst, Clayton Mines, 16.vii.1996 (M.E. Yurlina); [ AMNH]; 1Ƥ13 Corson’s Inlet, 26.vii.1923 (J.C. Bradley); [ CUIC]; NEW YORK: 1Ƥ13 Suffolk Co., N41.02621 W071.9633, 7.ix.2005 (S.W. Droege); 1Ƥ Suffolk Co., N41.03537 W071.1363, 7.ix.2005 (S.W. Droege); 13 Suffolk Co., N41.1279 W071.2716, 8.ix.2005 (S.W. Droege); [ PCYU]; NORTH CAROLINA: 1Ƥ Kill Devil Hills, 4.viii.1962 (K.V. Krombein); [ CUIC]; 1Ƥ Kill Devil Hills, 8.ix.1956 (T.B. Mitchell); [ NCSU]; 1Ƥ Dare Co., N36.0306 N075.6764, 13.vii.2006 (E. Soderholm); [ PCYU]; VIR- GINIA: 5ƤƤ Assateague I., N37.9808 W075.2808, 30.vi–1.vii.2006 (S.W. Droege); 1Ƥ Assateague I., N37.8815 W075.3461, 1–2.vii.2006 (S.W. Droege); [ PCYU].

Floral records. AMARANTHACEAE : Alternanthera flavescens ; ASTERACEAE : Bidens , Chrysopsis falcata , Helianthus debilis ; VITACEAE : Parthenocissus .

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon. Lasioglossum marinum is a sand dune specialist only collected on the coast of the eastern United States from Alabama to New York. This species shows affinities to other presumed sand dune specialists in North America, such as L. sheffieldi and L. yukonae , both of which have a slightly elongate tegula ( Gibbs 2010b). The enlarged tegula of L. marinum is similar to those of the L. tegulare species-group but L. marinum is only distantly related ( Gibbs 2009a).

Figures

FIGURE 155. Lasioglossum marinum (Crawford) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 156. Lasioglossum marinum (Crawford) female, dorsal view of mesosoma.

FIGURE 157. Lasioglossum marinum (Crawford) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 158. Lasioglossum marinum (Crawford) male terminalia, (A) ventral view, (B) dorsal view. Scale bar = 0.5 mm.

FIGURE 159. Distribution map of Lasioglossum marinum (circles) and L. miniatulum (stars).