Lasioglossum (Dialictus) georgeickworti Gibbs

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 100-103

publication ID 10.5281/zenodo.1049595

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Lasioglossum (Dialictus) georgeickworti Gibbs

new species

Lasioglossum (Dialictus) georgeickworti Gibbs , new species

( Figures 110–114 View FIGURE 110 View FIGURE 111 View FIGURE 112 View FIGURE 113 View FIGURE 114 )

Holotype. 1 Ƥ USA, Massachusetts, Franklin Co., Montague WMA, gravel pit, N 42.56957 W072.53617, 29–30.vii. 2008 (J. Milam); [ PCYU].

Diagnosis. Female L. georgeickworti have a unique T 1 acarinarial fan, which lacks a dorsal opening but has an inverted triangle-shaped glabrate area subdorsally. Additional characters for distinguishing L. georgeickworti include head wider than long (length/width ratio = 0.97–0.98); mesoscutal punctures sparse between parapsidal lines (i= 1–2 d) ( Fig. 111 View FIGURE 111 ); mesepisternum rugulose, obscurely punctate (i= 1–1.5 d); metapostnotal rugae reaching posterior margin; metasomal terga with distinct punctures throughout (i= 1–2 d); T 2 –T 3 basolaterally and T 4 entirely with tomentum ( Fig. 110 View FIGURE 110 A); apical impressed areas amber basally, translucent pale brownish yellow apically.

Male L. georgeickworti can be recognised by the following diagnostic combination: head slightly elongate (length/ width ratio = 1.01–1.03); face below eye emargination with dense tomentum ( Fig. 112 View FIGURE 112 B); mesoscutum polished, punctures moderately sparse between parapsidal lines (i= 1–2 d); mesepisternum with relatively distinct punctures; tegula and tarsi orange to brownish yellow ( Fig. 112 View FIGURE 112 A); metapostnotal rugae reaching angulate posterior margin ( Fig. 113 View FIGURE 113 ); and metasomal terga with apical impressed areas virtually impunctate.

Description. FEMALE. Length 5.26–5.57 mm; head length 1.49–1.64 mm; head width 1.52–1.68 mm; forewing length 3.45–3.69 mm.

Colouration. Head and mesosoma pale blue, sometimes greenish blue. Clypeus basal half blackish brown. Antenna dark brown, flagellum with ventral surface reddish brown, F 8 –F 10 sometimes with ventral surface orange-yellow. Tegula amber to reddish brown. Wing membrane hyaline, venation and pterostigma pale brownish yellow. Legs brown, except medio- and distitarsi reddish brown. Metasoma dark brown, terga and sterna with apical margins amber to translucent brownish yellow.

Pubescence. Dull white. Moderately sparse. 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 and gena with sparse, subappressed tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with dense, fine hairs. T 1 acarinarial fan large without dorsal opening but interrupted subdorsally with glabrate patch. T 2 –T 3 basolateral portions and T 4 entirely with tomentum partially obscuring surface. T 2 apicolateral and T 3 –T 4 apical margins with relatively dense apical fringes.

Surface sculpture. Face weakly imbricate, punctation moderately fine. Clypeus with apical half polished, punctation sparse (i= 1–3 d). Supraclypeal area with punctation sparse (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 obscurely punctate (i= 1–1.5 d). Gena polished, weakly lineolate. Postgena polished. Mesoscutum weakly imbricate, polished posteriorly, punctation fine, moderately sparse between parapsidal lines (i= 1–2 d), dense laterad of parapsidal line (i≤d), reticulate on anterolateral portion. Mesoscutellum similar to mesoscutum, submedial punctation sparse(i= 1–4 d). Axilla punctate. Metanotum rugulose-imbricate. Preëpisternum rugulose. Hypoepimeral area imbricate. Mesepisternum dorsal portion rugulose-imbricate, ventral portion weakly imbricate, punctation obscure (i= 1–1.5 d). Metepisternum with dorsal portion carinulate, ventral portion imbricate. Metapostnotum rugoso-carinulate, nearly reaching posterior margin. Propodeum with dorsolateral slope imbricate, lateral and posterior surfaces tessellate-imbricate. Metasomal terga polished, punctation dense and distinct throughout (i= 1–2 d).

Structure. Head wide to elongate (length/width ratio = 0.97–0.98). Eyes convergent below (UOD/LOD ratio = 1.21– 1.24). Clypeus 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 narrower than eye. Inner metatibial spur pectinate with 3– 4 branches. Metapostnotum moderately elongate (MMR ratio = 1.21–1.25), 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 4.54–5.32 mm; head length 1.37–1.56 mm; head width 1.36–1.51 mm; forewing length 3.45–3.81 mm.

Colouration. Labrum and mandible amber. Clypeus with distal margin narrowly amber. Flagellum with ventral surface brownish yellow. Pterostigma reddish brown. Legs brown, except tibial apices, metatibial base and tarsi yellowish brown.

Pubescence. Paraocular area below eye emargination and clypeus basally with dense tomentum obscuring surface. T 2 –T 4 basolaterally with sparse, scattered tomentum. S 3 apically and S 4 –S 5 laterally with moderately dense plumose hairs oriented posteromedially (1–1.5 OD).

Surface sculpture. Metanotum rugose. Preëpisternum and hypoepimeral area rugulose. Mesepisternum with dorsal portion rugulose-punctate, ventral portion weakly imbricate-punctate. Metapostnotum coarsely and completely rugose. Propodeum rugose. Metasomal terga with apical impressed areas impunctate, at most a few scattered punctures.

Structure. Head slightly elongate (length/width ratio = 1.01–1.03). Eyes strongly convergent below (UOD/LOD ratio = 1.46–1.57). Labrum not emarginate. Antennal sockets moderately distant (IAD/OAD> 1.3). Frontal line carinate, ending 2 OD below median ocellus. Pedicel shorter than F 1. F 2 length 1.8–2.1 X F 1. F 2 –F 10 moderately elongate (length/ width ratio = 1.57–1.80). Metapostnotum elongate (MMR ratio = 1.12–1.19), posterior margin sharply angled onto posterior surface.

Terminalia . S 7 with median lobe columnar, apex rounded ( Fig. 114 View FIGURE 114 ). S 8 with apicomedial margin weakly convex ( Fig. 114 View FIGURE 114 ). Genital capsule as in Fig. 114 View FIGURE 114 . Gonobase with ventral arms narrowly separated. Volsella roughly ovoid. Gonostylus small, dorsal setae elongate. Retrorse lobe narrow, attenuated and recurved apically.

Range. Coastal regions of Massachusetts, PEI, south to Virginia ( Fig. 115 View FIGURE 115 ). USA: CT, DE, MA, NJ, NY, VA. CAN- ADA: PE.

Allotype. USA: DELAWARE: 13 New Castle Co., N 39.5445 W075.5761, (S.W. Droege); [ PCYU].

Paratypes. USA: CONNECTICUT: 1 Ƥ Mansfield Twp., nr. Chapins Pond, 1.v. 1973 (G.I. Stage); [ AMNH]; MAS- SACHUSETTS: 4 ƤƤ Franklin Co., Montague WMA, gravel pit # 4, N 42.56862 W072.53409, 13– 2009 (J. Milam); 1 Ƥ Franklin Co., Montague WMA, gravel pit # 4, N 42.56862 W072.53409, 18– 2010 (J. Milam); 7 ƤƤ Franklin Co., Montague WMA, gravel pit # 4, N 42.56862 W072.53409, 24– 2009 (J. Milam); 1 Ƥ Franklin Co., Montague WMA, gravel pit # 4, N 42.56862 W072.53409, 5– 2009 (J. Milam); 5 ƤƤ Franklin Co., Montague WMA, large gravel pit, N 42.56957 W072.53617, 22–23.vii. 2010 (J. Milam); 1 Ƥ Franklin Co., Montague WMA, large gravel pit, N 42.56957 W072.53617, 29–30.vii. 2008 (J. Milam); 1 Ƥ Franklin Co., Montague WMA, gravel pit # 3, N 42.57277 W072.53865, 1– 2.vii. 2010 (J. Milam); 1 Ƥ Franklin Co., Montague WMA, Pt. 44, scrub oak, N 42.56701 W072.53274, 18– 2010 (J. Milam); 1 Ƥ Plymouth Co., Halifax, Burrage Pond WMA, N 42 °0ʹ 44 ʹʹ W080° 52 ʹ 23 ʹʹ, 2010 (J. Milam); [ CUIC]; 1 Ƥ Middlesex Co., 0.5 mi S. of Townsend, sand pit, 5.viii. 2006 (M.F. Veit); 3 ƤƤ Parker River NWR, N 42.7719 W 70.8057, 21–22.viii. 2008 (D.B.); 1 Ƥ Plymouth Co., Plymouth, Myles Standish St. Forest, 14.vii. 2006 (M.F. Veit); [ PCYU]; NEW JERSEY: 1 Ƥ Burlington Co., Woodland Twp., S of Chatsworth, Franklin Parker Preserve, N 38 ˚ 48.379 ʹ W 74 ˚ 32.655 ʹ, 2007 (L.F. Henderson); [ ANSP]; 1 Ƥ Seaside Park “ 5–15 ” (Weiss & West); [ CNC]; 1 Ƥ Burlington Co., N 39.4201 W 74.6797, 2010 (T. Harrison); [ CUIC]; NEW YORK: 1 Ƥ Nassau Co., Tobay Beach, 24– 1976 (G.C. Eickwort); 1 Ƥ Nassau Co., Tobay Beach, in nest, 1976 (G.C. Eickwort); 1 Ƥ Nassau Co., Tobay Beach, 28.vii. 1974 (G.C. Eickwort); [ CUIC]; 1 Ƥ Suffolk Co., 6.ix. 2005 (S.W. Droege); 1 Ƥ Suffolk Co., N 40.99749 W072.0744, 7.ix. 2005 (S.W. Droege); 1 Ƥ Suffolk Co., N 41.1279 W072.2716, 8.ix. 2005 (S.W. Droege); [ PCYU]; VIRGINIA: 1 Ƥ Accomack Co., N 37.9456 W 75.3081, 10.viii. 2008 (W. Schmitz); 1 Ƥ Assateague I., N 37.9808 W075.2808,– 1.vii. 2006 (S.W. Droege); [ PCYU].

Additional specimens examined. CANADA: PRINCE EDWARD ISLAND: 1 Ƥ Queen’s Co., Anderson Road, N 46 ° 24 ʹ 37 ʹʹ W062° 53 ʹ 45 ʹʹ, 14 m, 5.viii. 2004 (S.K. Javorek); [ ACNS].

Floral records. FABACEAE : Baptisia ; SCROPHULARIACEAE : Lindernia .

Etymology. The specific epithet is named for the late George C. Eickwort for his studies of the Halictidae , including Dialictus nesting biology, socio-biology, and taxonomy.

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon. Lasioglossum georgeickworti seems to be a specialist of coastal areas and dunes in the Northeast. A single female was collected on Prince Edward Island; with additional sampling it should be possible to find records from more New England states and eastern Canada.


The Packer Collection at York University


American Museum of Natural History


Cornell University Insect Collection


University of Newcastle


Academy of Natural Sciences of Philadelphia


Canadian National Collection of Insects, Arachnids, and Nematodes


Agriculture Canada Nova Scotia


Department of Natural Resources, Environment, The Arts and Sport