Lasioglossum (Dialictus) abanci (Crawford)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 33-38

Lasioglossum (Dialictus) abanci (Crawford)

( Figures 39–43 )

Halictus abanci Crawford 1932: 71 . Ƥ.

Holotype. Ƥ USA, North Carolina, Swain Co., Andrews Bald, Mt. 6000 ft., 26.vii.1923 (J.C. Crawford); [ NMNH: 40305]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) abanci , p. 1111 (catalogue); Mitchell, 1960: Dialictus abanci Ƥ, p. 376 (redescription); Krombein, 1967: Lasioglossum (Dialictus) abanci , p. 462 (catalogue); Hurd, 1979: Dialictus abanci , p. 1963 (catalogue); Moure & Hurd, 1987: Dialictus abanci , p. 97 (catalogue).

Diagnosis. Female L. abanci can be recognised by the following diagnostic combination: head round to slightly elongate (length/width ratio = 1.00–1.02); mesoscutum polished due to weak microsculpture, punctures sparse between parapsidal lines (i=1–2.5d), denser laterad of parapsidal line (i=1–1.5d); tegula reddish brown; mesepisternum rugulose, obscurely punctate; metapostnotum with distinct medial carina and weak submedial rugae not extending more than 2/3 distance to posterior margin ( Fig. 40 ); T1 acarinarial fan with wide dorsal opening ( Fig. 40 ); metasomal terga brown, polished due to weak microsculpture, apical halves nearly impunctate, T2 basomedially with sparse punctures (i=2–5d); T2– T3 basolaterally and T4 entirely with very sparse tomentum and weak apical fringes. They are similar to L. planatum and L. oblongum , both of which have mesoscutum dull due to microsculpture and mesepisternum impunctate. Female L. oblongum have coarser metapostnotal rugae. Female L. subviridatum and L. taylorae are also similar but have denser punctation on metasomal terga. Female L. taylorae also have head elongate.

Male L. abanci can be recognised by the following diagnostic combination: head elongate (length/width ratio = 1.04–1.06); facial tomentum limited to lower paraocular area; F2–F10 elongate (length/width ratio = 1.86–2.08); mesoscutum polished, punctures fine, sparse between parapsidal lines (i=1–2.5d) ( Fig. 42 ); mesepisternum rugulose; tarsi reddish brown; metasomal terga without tomentum; apical impressed areas impunctate, and S3 with sparse apical pubescence. They are most similar to L. laevissimum and L. subviridatum , both of which have brownish yellow tarsi. Male L. laevissimum also have dense pubescence across S3.

Redescription. FEMALE. Length 5.45–6.23 mm; head length 1.51–1.70 mm; head width 1.51–1.66 mm; forewing length 4.66–4.72 mm.

Colouration. Head and mesosoma blue with green reflections. Clypeus with apical half blackish brown and basal half, and supraclypeal area greenish. Antenna dark brown, flagellum with ventral surface reddish brown. Tegula translucent reddish brown. Wing membrane subhyaline, venation and pterostigma dark amber. Legs dark brown, except medio- and distitarsi ferruginous. Metasoma blackish brown, terga and sterna with apical margins reddish brown.

Pubescence. Dull white. Sparse. Head and mesosoma with moderately dense woolly hairs (1–1.5 OD), longest on genal beard, metanotum, and mesopleuron (1.5–2 OD). Lower paraocular area and gena without subappressed tomentum. Propodeum with dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with sparse, fine hairs. T1 acarinarial fan with dorsal opening wider than lateral hair patches. T2–T3 basolaterally and T4 basally with at most small patch of tomentum. T2 apicolateral and T3–T4 apical margins with very sparse apical fringes, virtually absent.

Surface sculpture. Face imbricate, punctation fine. Clypeus polished, basal margin weakly imbricate, punctation sparse (i=1–3d). Supraclypeal area polished medially, punctation sparse (i=1–3.5d). Lower paraocular area and antennocular area punctation moderately sparse (i=1–1.5d). Upper paraocular area and frons reticulate-punctate.

Ocellocular area punctation obscure (i=1–1.5d). Gena lineolate. Postgena weakly imbricate. Mesoscutum polished, imbricate medially, punctation fine, moderately sparse between parapsidal lines (i=1–2.5d), relatively sparse laterad of parapsidal line (i=1–1.5d), dense on anterolateral portion (i≤d). Mesoscutellum polished, submedial punctation sparse (i=2–5d). Axilla punctate. Metanotum ruguloso-imbricate. Preëpisternum rugulose. Hypoepimeral area imbricate, obscurely punctate (i=1–1.5d). Mesepisternum dorsal half rugulose, obscurely punctate (i=1–2d), ventral half ruguloseimbricate. Metepisternum with dorsal half rugoso-carinulate, ventral half imbricate. Metapostnotum rugoso-carinulate, medial carina nearly reaching posterior margin, submedial rugae not extending more than 2/3 distance to posterior margin. Propodeum with dorsolateral slope rugulose-imbricate, lateral surface imbricate-tessellate, posterior surface tessellate. Metasomal terga polished except weakly coriarious on apical margins, punctation on basal halves sparse (i=1–2d), especially medially (i=1–4d), absent from apical half except along premarginal line and apicolaterally.

Structure. Head round (length/width ratio = 1.00–1.02). Eyes weakly convergent below (UOD/LOD ratio = 1.14– 1.17). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2.5–3 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 3–5 branches. Metapostnotum moderately elongate (MMR ratio = 1.21–1.26), posterior margin narrowly rounded onto posterior surface. Propodeum with oblique carina very weak, lateral carina weak, not reaching dorsal surface.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length. 5.32–5.75 mm; head length. 1.56–1.63 mm; head width. 1.48–1.57 mm; forewing length. 4.48–4.54 mm.

Colouration. Head blackish blue. Mesosoma greenish except propodeum bluish. Flagellum with ventral surface bright orange-yellow. Tegula reddish brown with amber margin. Pterostigma reddish brown. Legs brown, except tarsi reddish brown.

Pubescence. Lower paraocular area width moderately dense tomentum partially obscuring surface. Gena without evident tomentum. S3 apicolaterally and S4–S5 laterally with moderately dense patches of plumose hairs (1–1.5 OD).

Surface sculpture. Clypeal punctation sparse (i=1–3d). Metanotum rugose. Metapostnotum coarsely rugoso-carinulate, reaching posterior margin. Propodeum with dorsolateral slope, lateral surface and posterior surface rugose.

Structure. Head relatively elongate (length/width ratio = 1.04–1.06). Eyes strongly convergent below (UOD/LOD ratio = 1.46). Clypeus 1/2 below suborbital tangent, apicolateral margins weakly convergent. Supraclypeal area elongate. Antennal sockets distant (IAD/OAD> 1.2). Frontal line carinate, ending 1.5–2 OD below median ocellus. Pedicel shorter than F1. F2 length 1.9–2.1X F1. F2–F10 elongate (length/width ratio = 1.86–2.08). Metapostnotum with dorsal surface relatively short (MMR ratio = 1.20–1.33), posterior margin sharply angled onto posterior surface.

Terminalia . S7 with median lobe columnar, apex rounded ( Fig. 43 ). S8 with apicomedial margin weakly convex ( Fig. 43 ). Genital capsule as in Fig. 43 . Gonobase with ventral arms narrowly separated. Gonostylus small. Retrorse lobe elongate, attenuated apically.

Range. Wisconsin to Georgia ( Fig. 44 ). USA: GA, IL, IN, NC, NY, WI, WV.

Additional material examined. USA: GEORGIA: 13 Rabun Bald, 9.viii.1957 (L.A. Kelton); [ CNC]; 1Ƥ Rabun Bald, 2.vii.1938 (P.W. Fattig); 1Ƥ Sarah, 2.vi.1945 (P.W. Fattig); 1Ƥ Wayah Bald, 11.vii.1938 (T.B. Mitchell); [ NCSU]; ILLI- NOIS: 1Ƥ Urbana, 14.iv.1907; [ INHS]; INDIANA: 1Ƥ Porter Co., Indiana Dunes N.L., Howe’s prairie, N41˚39ʹ0 9ʹʹ W087˚4ʹ15ʹʹ, 5.viii.2004 (R. Grundel); [ IDNL]; NEW YORK: 1Ƥ Albany Co., Rensselaerville, N42.51611 W074.13833, 21.vi.2008, (M.A. Rozen); [ AMNH]; 4ƤƤ Tompkins Co., Ithaca vicinity, Carter Creek Rd., 15.vi.1997 (B.N. Danforth); [ CUIC]; NORTH CAROLINA: 1Ƥ Base of Wayah Bald, 10.viii.1957 (W.R. Richards); 1Ƥ Highlands, 6.v.1957 (W.J. Brown); 1Ƥ Highlands, 1.vii.1957 (J.R. Vockeroth); 13 Highlands, 9.viii.1957 (L.A. Kelton); [ CNC]; 2ƤƤ Highlands, 23.vii.1958 (T.B. Mitchell); [ NCSU]; WEST VIRGINIA: 5ƤƤ Tazewell Co., 1 mi. S. Bluefield, 6.vi.1976 (A. Lindsey); [ CUIC];; 2ƤƤ Hardy Co., Lost River S.P., 24.vi.1951 (K.V. Krombein); [ NCSU]; WISCONSIN: 3ƤƤ Grant Co., T6N, R6W, S17, 12–19.vii.1976, Gypsy Moth-M.T. [ IRCW].

Floral records. APIACEAE : Thaspium barbinode ; ASTERACEAE : Krigia , Rudbeckia ; FABACEAE : Melilotus ; ROSACEAE : Aruncus , Fragaria , Rubus ; RUBIACEAE : Houstonia purpurea .

DNA Barcode. Unavailable.

Comments. Uncommon.

The identity of L. abanci has been uncertain for a long time. Mitchell (1960) suggested that L. abanci may only be a form of L. oblongum . The identity of the latter species has also been uncertain and the name has been over applied in the past ( Gibbs 2010b). The large range distribution attributed to L. abanci previously ( Mitchell 1960; Moure & Hurd 1987) was in part due to misidentification of other species such as L. oblongum , L. planatum , and L. subviridatum . Material from near the type locality of L. abanci clearly match the holotype. Despite examination of many thousands of specimens of Lasioglossum (Dialictus) , including many near and around the type locality, only a small number of L. abanci have been found in collections.

Figures

FIGURE 39. Lasioglossum abanci (Crawford) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 40. Lasioglossum abanci (Crawford) female, dorsal view of mesosoma.

FIGURE 41. Lasioglossum abanci (Crawford) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 42. Lasioglossum abanci (Crawford) male, dorsal view of mesosoma.

FIGURE 43. Lasioglossum abanci (Crawford) male terminalia, (A) ventral view, (B) dorsal view. Scale bar = 0.5 mm.

FIGURE 44. Distribution map of Lasioglossum abanci (circles) and L. alachuense (stars).