Lasioglossum (Dialictus) gotham Gibbs

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 104-108

publication ID 10.5281/zenodo.1049595

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Lasioglossum (Dialictus) gotham Gibbs

new species

Lasioglossum (Dialictus) gotham Gibbs , new species

( Figures 116–119 View FIGURE 116 View FIGURE 117 View FIGURE 118 View FIGURE 119 )

Holotype. Ƥ USA, Maryland, Charles Co., N 38.6861 W077.0791, 23–24.iv. 2003 (S.W. Droege); [ PCYU].

Diagnosis. Female L. gotham can be recognised by the following diagnostic combination: size large (6.1–7.1 mm); head wide (length/width ratio = 0.95–0.97) ( Fig. 116 View FIGURE 116 B); mesoscutum polished, punctures sparse between parapsidal lines ( Fig. 117 View FIGURE 117 ); mesepisternum rugulose, obscurely punctate; T 1 acarinarial fan with narrow dorsal opening ( Fig. 117 View FIGURE 117 ); and metasomal terga brown, punctate on apical impressed areas. They are most similar to L. laevissimum and L. smilacinae . Female L. laevissimum have apical halves of metasomal terga impunctate. Female L. smilacinae have the mesosoma dull and blue, and T 1 acarinarial fan complete dorsally.

Males of L. gotham are similar to females and may be further distinguished by head moderately wide (length/width ratio = 0.97); face below eye emargination with relatively dense tomentum obscuring surface ( Fig. 118 View FIGURE 118 B); flagellomeres elongate (length/width ratio = 1.86 –2.00); mesoscutum polished, punctation sparse (i= 1–5 d), fine ( Fig. 119 View FIGURE 119 ); mesepisternal punctures present; metasomal terga brown, without tomentum, and apical impressed areas impunctate except for narrow band of moderately dense punctures anteriorly. They are most similar to L. zephyrum and L. smilacinae . Male L. zephyrum have the metapostnotal posterior margin rounded and greenish reflections on the metasomal terga. Male L. smilacinae have only widely scattered punctation on apical impressed areas of metasomal terga.

Description. FEMALE. Length 6.05–7.08 mm. head length 1.66–1.78 mm. head width 1.73–1.87 mm. forewing length 4.84–5.20 mm.

Colouration. Head and mesosoma pale green with bluish reflections, especially on head. Clypeus with apical half blackish brown and basal half, and supraclypeal area golden. Antenna dark brown, F 8 –F 10 with ventral surface reddish brown to brownish yellow. Tegula amber. Wing membrane subhyaline, venation and pterostigma amber. Legs brown, except tarsi reddish brown. Metasoma blackish brown, terga and sterna with apical margins reddish brown.

Pubescence. Dull white. Mostly 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 and gena with sparse subappressed tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga moderately sparse, fine hairs. T 1 acarinarial fan with narrow dorsal opening. T 2 –T 3 basolaterally with dense tomentum obscuring surface. T 4 –T 5 with scattered tomentum across disc, not obscuring surface. T 2 –T 4 apicolateral margins with very sparse apical fringe.

Surface sculpture. Face weakly imbricate, punctation moderately coarse. Clypeus polished, punctation sparse (i= 1– 2.5 d). Supraclypeal area with punctation moderately dense (i= 1–1.5 d). Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i<1.5 d). Upper paraocular area and frons reticulate-punctate. Ocellocular area minutely punctate (i≤d). Gena weakly lineolate. Postgena imbricate. Mesoscutum polished, weakly imbricate medially, punctation moderately sparse between parapsidal lines (i= 1–2 d), dense mesad and laterad of parapsidal line (i≤d), contiguous on anterolateral portion. Mesoscutellum polished, submedial punctation moderately sparse (i= 1–2 d). Axilla punctate. Metanotum rugulose-reticulate. Preëpisternum rugulose. Hypoepimeral area reticulate. Mesepisternum dorsal half rugulose, ventral half imbricate, with obscure punctures (i= 1–1.5 d). Metepisternum with dorsal half rugosocarinulate, ventral half imbricate. Metapostnotum longitudinally carinulate, not reaching posterior margin, plicate laterally. Propodeum with dorsolateral slope rugulose, lateral and posterior surfaces tessellate-imbricate. Metasomal terga weakly coriarious, punctation on basal halves moderately dense (i= 1–2 d), sparse on apical halves (i= 2–4 d).

Structure. Head wide (length/width ratio = 0.95–0.97). Eyes convergent below (UOD/LOD ratio = 1.13–1.14). Clypeus 1 / 2 – 2 / 3 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2 OD below median ocellus. Gena width subequal to eye. Inner metatibial spur pectinate with 3–4 branches. Metapostnotum moderately elongate (MMR ratio = 1.14–1.25), posterior margin rounded onto posterior surface. Propodeum with oblique carina moderately strong, lateral carina moderately strong, reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.26 mm; head length 1.56 mm; head width 1.61 mm; forewing length 4.54 mm.

Colouration. Head and mesosoma pale blue. Flagellum with ventral surface brownish yellow. Pterostigma reddish brown. Legs brown, except tibial bases and apices, and tarsi brownish yellow.

Pubescence. Face below eye emargination with moderately dense tomentum, partially obscuring surface, densest on lower paraocular area. Gena with virtually no tomentum. Metasomal terga without tomentum. S 3 and S 4 –S 5 apicolateral portions with dense plumose hairs (1–1.5 OD).

Surface sculpture. Punctation fine. Clypeal punctation moderately dense (i= 1–2 d). Mesoscutal punctation sparse between parapsidal lines (i= 1–5 d). Mesoscutellar punctures sparse (i= 1–2.5 d). Hypoepimeral area imbricate, obscurely punctate. Mesepisternum with dorsal portion ruguloso-punctate and ventral portion distinctly punctate (i= 1–2 d). Metapostnotum coarsely rugoso-carinulate, reaching posterior margin. Metasomal terga polished, punctation distinct throughout (i= 1–2 d), except apical portion of the apical impressed areas impunctate.

Structure. Head moderately wide (length/width ratio = 0.97). Eyes strongly convergent below (UOD/LOD ratio = 1.49). Clypeus 2 / 3 below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets distant (IAD/ OAD> 1.4). Frontal line carinate, ending 1.5 OD below median ocellus. Pedicel shorter than F 1. F 2 length 2.0X F 1. F 2 – F 10 elongate (length/width ratio = 1.86 –2.00). Metapostnotum moderately elongate (MMR ratio = 1.15), posterior margin narrowly rounded onto posterior surface.

Terminalia . S 7 with median lobe clavate, nearly parallel-sided. S 8 with apicomedial margin weakly convex. Genital capsule similar to L. smilacinae (see Gibbs 2010 b). Gonobase with ventral arms widely separated. Volsella roughly ovoid. Gonostylus short. Retrorse lobe elongate, attenuated apically.

Range. Pennsylvania to Georgia ( Fig. 120 View FIGURE 120 ). USA: GA, MD, NC, NY, PA, SC, VA.

Allotype. 3 USA, Maryland, Garrett Co., N 39.94722 W078.55, 7.vii. 2008 (J. Whittaker); [ PCYU].

Paratypes. USA: GEORGIA: 1 Ƥ Atlanta, 5.iii. 1938 (P.W. Fattig); 1 Ƥ Atlanta, 31.iii. 1940 (P.W. Fattig); 1 Ƥ Atlanta, 1941 (P.W. Fattig); 13 Atlanta, 1941 (P.W. Fattig); 2 ƤƤ Atlanta, 5.iii. 1944 (P.W. Fattig); 1 Ƥ Atlanta, 11.iii. 1945 (P.W. Fattig); 1 Ƥ Dallas, 11.iii. 1945 (P.W. Fattig); [ NCSU]; MARYLAND: 1 Ƥ Beltsville 27.ii. 1976 (S.W.T. Batra); 4 ƤƤ Beltsville, 1.iv. 1975 (S.W.T. Batra); 733 Beltsville, 1976 (S.W.T. Batra); [ CUIC]; 1 Ƥ Pr. George’s Co., N 38.9002 W076.674, 20.iv. 2002 (S.W. Droege); [ PCYU]; NEW YORK: 1 Ƥ Bronx Botanical Garden, 11.v. 1971 (J. Lin); 2 ƤƤ Kings Co., Brooklyn Botanical Garden, 18.vii. 2009 (J.S. Ascher); [ AMNH]; NORTH CAROLINA: 1 Ƥ Black Mts., 1911 “Ac. 33827 ”; [ AMNH]; 1 Ƥ Grandfather Mountain, 1954 (T.B. Mitchell); 1 Ƥ Raleigh, 15.v. 1961 (T.B. Mitchell); 1 Ƥ Raleigh, 10.iv. 1951 (T.B. Mitchell); 3 ƤƤ Raleigh, 1.iv. 1951 (E.G. Cummings); 1 Ƥ Sylva, 1952 (W.A. Stephen); 1 Ƥ Willard, 6.iv. 1951 (T.B. Mitchell); [ NCSU]; PENNSYLVANIA: 2 ƤƤ Huntingdon Co., Meadow Gap, 2005 (V. Giles); [ AMNH]; 1 Ƥ Bucks Co., N 40.4 W074.83, 5.viii. 2007 (J. Stager); [ PCYU]; SOUTH CAROLINA: 1 Ƥ Anderson Co., Pendleton, 250 m, Mat. Hardwood Forest, 17– 1987 ( BRC Hym. Team); 1 Ƥ Dorchester Co., Francis Beidler For., 10 km NE Harleyville, Bald Cypress Swamp, v–vi. 1987; [ CNC]; VIRGINIA: 4 ƤƤ Shenandoah N.P., Big Meadow, 1300 m, natural meadow, vi– 6.vii. 1987 ( BRC Hym. Team); 13 Warren Co., Shenandoah N.P., Compton Gap, 800 m,– 2.vii. 1987 ( BRC Hym. Team); [ CNC]; 1 Ƥ Arlington, 15.iv. 1951 (K.V. Krombein); [ NCSU].

Floral records. ACERACEAE : Acer rubrum ; BORAGINACEAE : Mertensia virginica ; CARYOPHYLLACEAE : Stellaria media ; FABACEAE : Trifolium sp.; GERANIACEAE : Geranium molle ; LAMIACEAE : Lamium amplexicaule ; RHAMNACEAE : Ceanothus ; ROSACEAE : Craetagus, Prunus ; VIOLACEAE : Viola bicolor .

Biology. Detailed studies of L. gotham phenology, nesting biology, socio-biology, floral hosts, and natural enemies was provided by Batra (1987; as D. laevissimus ).

Etymology. The specific epithet is named for the city of New York where some of the paratypes were collected. DNA barcode. Available. Multiple sequences.

Comments. Uncommon.


The Packer Collection at York University


North Carolina State University Insect Museum


Cornell University Insect Collection


University of Newcastle


American Museum of Natural History


Botanical Record Club


Canadian National Collection of Insects, Arachnids, and Nematodes


Department of Natural Resources, Environment, The Arts and Sport