Lasioglossum (Dialictus) apocyni (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 45-49

Lasioglossum (Dialictus) apocyni (Mitchell)

( Figures 51–55 )

Dialictus apocyni Mitchell, 1960: 381 . Ƥ.

Holotype. Ƥ USA, West Virginia, Raleigh Co., 6.vi.1955, on Apocynum cannabinum ; (H.V. Weems, Jr.); [ FSCA]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) apocyni , p. 462 (catalogue); Moure and Hurd, 1987: Dialictus apocyni , p. 90 (catalogue).

Diagnosis. Female L. apocyni can be recognised by the following diagnostic combination: clypeus flat, gena wider than eye ( Fig. 51 A), hypostomal carinae parallel, and T1 acarinarial fan open dorsally ( Fig. 52 ). In unworn specimens, the mandible extends beyond the opposing clypeal angle. They are most similar to L. katherineae and L. fattigi , both of which have clypeus less flat, gena subequal to eye, and in L. katherineae T1 acarinarial fan complete without dorsal opening.

Male L. apocyni can be recognised by the combination of head elongate (length/width ratio = 1.06–1.07); supraclypeal area longer than wide; pronotal ridge strong but rounded; mesoscutum entirely imbricate, punctation sparse between parapsidal lines ( Fig. 54 ); metapostnotum posterior margin rounded onto posterior declivitous surface; and metasomal terga with apical impressed areas impunctate. They are most similar to male L. fattigi , which have mesoscutum polished submedially.

Description. FEMALE. Length 3.87–5.08 mm; head length 1.37–1.58 mm; head width 1.39–1.61 mm; forewing length 3.03–3.63 mm.

Colouration. Head and mesosoma pale golden green, sometimes bluish. Clypeus with apical half blackish brown, basal half and supraclypeal area sometimes golden. Antenna dark brown, flagellum with ventral surface dark reddish brown. Tegula pale reddish brown to brownish yellow. Wing venation and pterostigma pale brownish yellow. Legs brown, except medio- and distitarsi reddish brown. Metasoma brown, terga and sterna with apical margins 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 virtually no tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with sparse, fine hairs. T1 acarinarial fan with narrow dorsal opening, not wider than lateral hair patches. T2–T3 basolaterally and T4 entirely with sparse tomentum not obscuring surface. T2 apicolateral and T3–T4 apical margins with sparse apical fringes.

Surface sculpture. Face weakly imbricate, punctation fine. Clypeus polished, punctation sparse (i=1–4d). Supraclypeal area with punctation sparse (i=1–4d). Lower paraocular and antennocular areas with punctation relatively sparse (i=1–2.5d). Upper paraocular area and frons contiguously punctate. Ocellocular area minutely, obscurely punctate (i=1–1.5d). Gena weakly lineolate. Postgena weakly imbricate. Mesoscutum weakly tessellateimbricate, punctation fine, moderately sparse between parapsidal lines (i=1–2d), dense laterad of parapsidal line (i≤d), and reticulate on anterolateral portion. Mesoscutellum similar to mesoscutum, submedial punctation sparse (i=1–3d). Axilla punctate. Metanotum imbricate. Preëpisternum weakly rugulose. Hypoepimeral area imbricate. Mesepisternum weakly rugulose. Metepisternum dorsal ½ carinulate, lower ½ imbricate. Metapostnotum incompletely rugoso-carinulate, posterior margin tessellate-imbricate. Propodeum with dorsolateral slope imbricate, carinulate basally, lateral and posterior surfaces tessellate. Metasomal terga coriarious, T1 anterior surface with distinct microsculpture, punctation on basal halves moderately dense (i=1–1.5d), obscure and scattered on apical halves (i=2–2.5d), T1 dorsal portion and T2 apical half virtually impunctate.

Structure. Head round (length/width ratio = 0.98–0.99). Eyes weakly convergent below (UOD/LOD ratio = 1.11–1.18). Mandible often extending beyond opposing clypeal angle. Clypeus flat, ½ below suborbital tangent, apicolateral margins strongly convergent. Antennal sockets moderately close (IAD/OAD <0.6). Frontal line carinate, ending 2.5OD below median ocellus. IOD subequal to OOD. Gena wider than eye. Pronotal ridge strong, acarinate. Inner metatibial spur pectinate with 3 branches. Metapostnotum moderately elongate (MMR ratio = 1.40), posterior margin rounded onto posterior surface. Propodeum with oblique carina virtually absent, lateral carina weak, reaching halfway to dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length. 4.30–5.26 mm; head length. 1.32–1.49 mm; head width. 1.25–1.39 mm; forewing length. 2.96–3.32 mm.

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

Pubescence. Lower paraocular area with tomentum partially obscuring surface. Clypeus with scattered tomentum not obscuring surface. Gena with sparse tomentum. S3–S5 with apicolateral patches of appressed hairs.

Surface sculpture. Clypeal punctation relatively dense (i=1–1.5d). Metanotum rugose. Preëpisternum and hypoepimeral area rugulose. Metapostnotum with moderately strong rugae nearly reaching posterior margin. Propodeum with dorsolateral slope rugose, lateral and posterior surfaces ruguloso-imbricate. Metasomal terga polished, punctation moderately dense (i=1–2d) nearly reaching premarginal line, apical impressed areas impunctate.

Structure. Head elongate (length/width ratio = 1.06–1.07). Eyes strongly convergent below (UOD/LOD ratio = 1.58– 1.67). Supraclypeal area below antennal sockets longer than wide (length/width ratio = 1.2). Antennal sockets distant (IAD/OAD> 1.4). Frontal line carinate, ending 2OD below median ocellus. Pedicel shorter than F1. F2 length 1.7X F1. F2–F10 moderately elongate (length/width ratio = 1.64–1.81). Propodeum dorsal surface moderately elongate (MMR ratio = 1.26), posterior margin rounded onto posterior surface.

Terminalia . Genital capsule as in Fig. 55 . Gonobase with ventral arms widely separated. Gonostylus small, dorsal setae elongate. Retrorse lobe elongate, attenuated apically.

Range. Indiana to West Virginia, south to Tennessee ( Fig. 56 ). USA: IL, IN, KY, MS, OH, TN, VA, WV.

Additional material examined. USA: ILLINOIS: 1Ƥ Cook Co., Elgin, Bluff Springs Fen, 28.vi.2010 (L. Rericha); [ CUIC]; 1Ƥ Peoria Co., Peoria Heights, 19.viii.1968 (J.C. Marlin); 1Ƥ Tazewell Co., 3 mi N. Mackinaw, 10.vi.1969 (Webb & Marlin); 1Ƥ Woodford Co., 2 mi W Metamora, 16.viii.1968 (J.C. Marlin); [ INHS]; INDIANA: 1Ƥ Morgan- Monroe S.F., 14–16.vii.1937 (Montgomery 1937 Forest Insect Survey); [ NCSU]; 1Ƥ Vigo Co., 11.v.1999 (R.P. Jean); [ PCYU]; MISSISSIPPI: 8ƤƤ Pontotoc Co., 1 mi. SE Escru, 4.vi.1981 (M. O. Mann); [ CUIC]; OHIO: 2ƤƤ paratypes Coshocton Co., 2.vi.1929 (J.S. Hine); [ NCSU]; TENNESSEE: 1Ƥ Roane Co., 5.ix.1982 ( O. Pellmyr); [ CUIC]; VIR- GINIA: 1Ƥ Eagle Rock, 18.vi.1957 (R.L. Fischer); [ MSUC]; WEST VIRGINIA: 1Ƥ paratype Raleigh Co., 4.vi.1955 (H.V. Weems, Jr.); [ AMNH]; 16ƤƤ paratypes Raleigh Co., 6.vi.1955 (H.V. Weems, Jr.); [ NCSU]; 1Ƥ paratype Raleigh Co., 4.vi.1955 (H.V. Weems, Jr.); [ NMNH]; 2ƤƤ Hampshire Co., N39.34105 W078.4641, 29–30.v.2004 (S.W. Droege); 1Ƥ Hampshire Co., N39.23486 W078.7442, 11.vii.2005 (S.W. Droege); 1Ƥ Hampshire Co., N39.27931 W078.6809, 11.vii.2005 (S.W. Droege); 3ƤƤ Hampshire Co., N39.3348 W078.458, 20.x (S.W. Droege); 13 Hampshire Co., N39.2489 W078.5256, 9.xi.2007 (V. Schoene); 3ƤƤ 233 near Charleston, N38.41211 W081.64776, 15.viii.2006 (J. Gibbs); [ PCYU].

Floral records. APIACEAE : Daucus carota ; APOCYNACEAE : Apocynum cannabinum ; RANUNCULACEAE : Actaea rubifolia .

DNA Barcode. Available. Multiple sequences. DNA barcodes do not clearly distinguish L. apocyni from L. fattigi or L. paradmirandum .

Comments. Uncommon.

Figures

FIGURE 51. Lasioglossum apocyni (Mitchell) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 52. Lasioglossum apocyni (Mitchell) female, dorsal view of mesosoma.

FIGURE 53. Lasioglossum apocyni (Mitchell) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 54. Lasioglossum apocyni (Mitchell) male, dorsal view of mesosoma.

FIGURE 55. Lasioglossum apocyni (Mitchell) male terminalia, (A) ventral view, (B) dorsal view. Scale bar = 0.5 mm.

FIGURE 56. Distribution map of Lasioglossum apocyni (circles) and L. apopkense (stars).