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

Lasioglossum (Dialictus) georgeickworti Gibbs , new species

( Figures 110–114 )

Holotype. 1Ƥ USA, Massachusetts, Franklin Co., Montague WMA, gravel pit, N42.56957 W072.53617, 29–30.vii.2008 (J. Milam); [ PCYU].

Diagnosis. Female L. georgeickworti have a unique T1 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=1–2d) ( Fig. 111 ); mesepisternum rugulose, obscurely punctate (i=1–1.5d); metapostnotal rugae reaching posterior margin; metasomal terga with distinct punctures throughout (i=1–2d); T2–T3 basolaterally and T4 entirely with tomentum ( Fig. 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 B); mesoscutum polished, punctures moderately sparse between parapsidal lines (i=1–2d); mesepisternum with relatively distinct punctures; tegula and tarsi orange to brownish yellow ( Fig. 112 A); metapostnotal rugae reaching angulate posterior margin ( Fig. 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, F8–F10 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. T1 acarinarial fan large without dorsal opening but interrupted subdorsally with glabrate patch. T2–T3 basolateral portions and T4 entirely with tomentum partially obscuring surface. T2 apicolateral and T3–T4 apical margins with relatively dense apical fringes.

Surface sculpture. Face weakly imbricate, punctation moderately fine. Clypeus with apical half polished, punctation sparse (i=1–3d). Supraclypeal area with punctation sparse (i=1–1.5d). Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i≤1.5d). Upper paraocular area and frons reticulate-punctate. Ocellocular area obscurely punctate (i=1–1.5d). Gena polished, weakly lineolate. Postgena polished. Mesoscutum weakly imbricate, polished posteriorly, punctation fine, moderately sparse between parapsidal lines (i=1–2d), dense laterad of parapsidal line (i≤d), reticulate on anterolateral portion. Mesoscutellum similar to mesoscutum, submedial punctation sparse(i=1–4d). Axilla punctate. Metanotum rugulose-imbricate. Preëpisternum rugulose. Hypoepimeral area imbricate. Mesepisternum dorsal portion rugulose-imbricate, ventral portion weakly imbricate, punctation obscure (i=1–1.5d). 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=1–2d).

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. T2–T4 basolaterally with sparse, scattered tomentum. S3 apically and S4–S5 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 F1. F2 length 1.8–2.1X F1. F2–F10 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 . S7 with median lobe columnar, apex rounded ( Fig. 114 ). S8 with apicomedial margin weakly convex ( Fig. 114 ). Genital capsule as in Fig. 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 ). USA: CT, DE, MA, NJ, NY, VA. CAN- ADA: PE.

Allotype. USA: DELAWARE: 13 New Castle Co., N39.5445 W075.5761, 21.vi (S.W. Droege); [PCYU].

Paratypes. USA: CONNECTICUT: 1Ƥ Mansfield Twp., nr. Chapins Pond, 1.v.1973 (G.I. Stage); [AMNH]; MAS- SACHUSETTS: 4ƤƤ Franklin Co., Montague WMA, gravel pit #4, N42.56862 W072.53409, 13–14.vi.2009 (J. Milam); 1Ƥ Franklin Co., Montague WMA, gravel pit #4, N42.56862 W072.53409, 18–19.vi.2010 (J. Milam); 7ƤƤ Franklin Co., Montague WMA, gravel pit #4, N42.56862 W072.53409, 24–25.vi.2009 (J. Milam); 1Ƥ Franklin Co., Montague WMA, gravel pit #4, N42.56862 W072.53409, 5–6.vi.2009 (J. Milam); 5ƤƤ Franklin Co., Montague WMA, large gravel pit, N42.56957 W072.53617, 22–23.vii.2010 (J. Milam); 1Ƥ Franklin Co., Montague WMA, large gravel pit, N42.56957 W072.53617, 29–30.vii.2008 (J. Milam); 1Ƥ Franklin Co., Montague WMA, gravel pit #3, N42.57277 W072.53865, 1– 2.vii.2010 (J. Milam); 1Ƥ Franklin Co., Montague WMA, Pt. 44, scrub oak, N42.56701 W072.53274, 18–19.vi.2010 (J. Milam); 1Ƥ Plymouth Co., Halifax, Burrage Pond WMA, N42°0ʹ44ʹʹ W080°52ʹ23ʹʹ, 11.vi.2010 (J. Milam); [CUIC]; 1Ƥ Middlesex Co., 0.5 mi S. of Townsend, sand pit, 5.viii.2006 (M.F. Veit); 3ƤƤ Parker River NWR, N42.7719 W70.8057, 21–22.viii.2008 (D.B.); 1Ƥ Plymouth Co., Plymouth, Myles Standish St. Forest, 14.vii.2006 (M.F. Veit); [PCYU]; NEW JERSEY: 1Ƥ Burlington Co., Woodland Twp., S of Chatsworth, Franklin Parker Preserve, N38˚48.379ʹ W74˚32.655ʹ, 12.vi.2007 (L.F. Henderson); [ANSP]; 1Ƥ Seaside Park “5–15” (Weiss & West); [CNC]; 1Ƥ Burlington Co., N39.4201 W74.6797, 22.vi.2010 (T. Harrison); [CUIC]; NEW YORK: 1Ƥ Nassau Co., Tobay Beach, 24–26.vi.1976 (G.C. Eickwort); 1Ƥ Nassau Co., Tobay Beach, in nest, 26.vi.1976 (G.C. Eickwort); 1Ƥ Nassau Co., Tobay Beach, 28.vii.1974 (G.C. Eickwort); [CUIC]; 1Ƥ Suffolk Co., 6.ix.2005 (S.W. Droege); 1Ƥ Suffolk Co., N40.99749 W072.0744, 7.ix.2005 (S.W. Droege); 1Ƥ Suffolk Co., N41.1279 W072.2716, 8.ix.2005 (S.W. Droege); [PCYU]; VIRGINIA: 1Ƥ Accomack Co., N37.9456 W75.3081, 10.viii.2008 (W. Schmitz); 1Ƥ Assateague I., N37.9808 W075.2808, 30.vi–1.vii.2006 (S.W. Droege); [PCYU].

Additional specimens examined. CANADA: PRINCE EDWARD ISLAND: 1Ƥ Queen’s Co., Anderson Road, N46°24ʹ37ʹʹ W062°53ʹ45ʹʹ, 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.

Figures

FIGURE 110. Lasioglossum georgeickworti Gibbs female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 111. Lasioglossum georgeickworti Gibbs female, dorsal view of mesosoma.

FIGURE 112. Lasioglossum georgeickworti Gibbs male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 113. Lasioglossum georgeickworti Gibbs male, dorsal view of mesosoma.

FIGURE 114. Lasioglossum georgeickworti Gibbs, new species male terminalia, (A) ventral view, (B) dorsal view. Scale bar = 0.5 mm.

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