Lasioglossum (Dialictus) alachuense (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 40-43

Lasioglossum (Dialictus) alachuense (Mitchell)

( Figure 47–50 )

Dialictus alachuensis Mitchell, 1960: 378 . Ƥ.

Holotype. Ƥ USA, Florida, Alachua Co., 20.ix.1955 (H.V. Weems, Jr.); [ FSCA]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) alachuense , p. 462 (catalogue); Moure and Hurd, 1987: Dialictus alachuensis , p. 88 (catalogue).

Diagnosis. Female L. alachuense can be recognised by the following diagnostic combination: apical half of clypeus brown to reddish-orange; mesoscutum imbricate-tessellate, punctures sparse between parapsidal lines (i=1–2.5d) ( Fig. 48 ); mesepisternum rugulose; tegula pale yellow; metatibia with extensive orange-yellow ( Fig. 47 A); metapostnotal rugae relatively fine; T1 fan with wide dorsal opening ( Fig. 48 ); and metasoma terga blackish brown with no appressed tomentum. They are superficially similar to L. leviense , which has sparse tomentum on metasomal terga.

Male L. alachuense can be recognised by the combination of clypeus with distal margin yellow ( Fig. 49 B); mesoscutum imbricate, punctation sparse between parapsidal lines (i=1–2.5d) ( Fig. 50 ); mesepisternum finely ruguloseimbricate; tegula pale yellow; tibiae and tarsi almost entirely brownish yellow; metasomal terga without tomentum, apical impressed areas impunctate; and S4–S5 with apicolateral hairs. They are most similar to L. leviense which are smaller, more finely rugulose on mesepisternum, and tibiae less extensively brownish yellow.

Redescription. FEMALE. Length 4.23–5.02 mm; head length 1.27–1.43 mm; head width 1.32–1.51 mm; forewing length 3.33–3.69 mm.

Colouration. Head and mesosoma pale green to blue. Clypeus with apical half blackish brown to reddish orange. Antenna dark brown, flagellum with ventral surface reddish brown. Tegula pale yellow. Wing membrane subhyaline, venation and pterostigma yellowish brown. Legs brown except tarsi, and apical and basal portions of tibiae yellow to amber, pro- and metatibiae sometimes with more extensive pale colouration. Metasoma dark brown, terga and sterna with apical margins translucent brownish yellow.

Pubescence. Dull white. Moderately sparse. Head and mesosoma with moderately sparse woolly hairs (1–2 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 with moderately sparse, fine hairs. T1 acarinarial fan limited to small lateral area, dorsal opening wider than lateral patches. T1–T6 without tomentum. T2 apicolateral and T3–T4 apical margins with sparse fringes.

Surface sculpture. Face imbricate, punctation fine. Clypeus with apical half polished, punctation sparse (i=1–3d). Supraclypeal area with punctation moderately sparse (i=1–2d). Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i=1–1.5d). Upper paraocular area and frons punctate-reticulate. Ocellocular area obscurely punctate (i=d). Gena obscurely lineolate. Postgena weakly imbricate. Mesoscutum weakly imbricate, punctation moderately sparse between parapsidal lines (i=1–2.5d), dense laterad of parapsidal line (i≤d), contiguous on anterolateral portion. Mesoscutellum similar to mesoscutum, submedial punctation sparse (i=1.5–3d). Axilla minutely punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area imbricate-rugulose. Mesepisternum dorsal half rugulose, ventral half ruguloso-imbricate. Metepisternum with upper half carinulate and ventral portion imbricate. Metapostnotum incompletely carinulate, posterior margin imbricate. Propodeum with dorsolateral slope imbricate, lateral surface tessellate-imbricate, posterior surface imbricate. Metasomal terga polished, punctation moderately dense basally (i=1– 1.5d), more widely spaced apically (i=1–2.5d).

Structure. Head very wide (length/width ratio = 0.94–0.96). Eyes convergent below (UOD/LOD ratio = 1.29–1.30). Clypeus ½ below suborbital tangent, apicolateral angle convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2–2.5 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 3–5 branches. Metapostnotum not truncate (MMR ratio = 1.00–1.14), posterior margin narrowly rounded onto posterior surface. Propodeum with oblique carina absent, lateral carina not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.75–4.88 mm; head length 1.45–1.48 mm; head width 1.50 mm; forewing length 4.13–4.19 mm.

Colouration. Labrum, mandible, and distal margin of clypeus brownish yellow. Flagellum with ventral surface reddish brown. Tegula brownish yellow. Legs brown, except tibiae mostly yellowish brown, tarsi pale brownish yellow.

Pubescence. Face below eye emargination with moderately dense tomentum partially obscuring surface. Metasomal sterna sparsely pubescent, S4–S5 with apicolateral tufts (1.5 OD).

Surface sculpture. Mesoscutum imbricate, punctation sparse between parapsidal lines (i=1–2.5d) and dense laterad of parapsidal line (i≤1d). Metapostnotum with coarse longitudinal rugae, separated by wide smooth interstitial regions. Propodeal dorsolateral slope coarsely rugose. T2 apical impressed area impunctate.

Structure. Head wide (length/width ratio = 0.97–0.98). Eyes strongly convergent below (UOD/LOD ratio = 1.57– 1.59). Clypeus 2/3 below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets distant (IAD/ OAD> 1.5). Frontal line carinate, ending 1.5 OD below median ocellus. Pedicel shorter than F1. F2 length 1.9X F1. F2– F10 elongate (length/width ratio = 1.73–1.90). Metapostnotum moderately elongate (MMR ratio = 1.13–1.17), posterior margin sharply angled onto posterior propodeal surface.

Terminalia . Not examined.

Range. South-eastern USA ( Fig. 44 ). USA: FL, GA.

Additional material examined. USA: FLORIDA: 3ƤƤ13 Leon Co., Apalachicola National Forest, FS366, LLP, N30.19751 W084.30309, 11–18.vii.2005 (Ronquist Lab); [ AMNH]; 1Ƥ paratype Alachua Co., 20.ix.1955; 1Ƥ Alachua Co., 20.ix.1955; 2ƤƤ Liberty Co., 2.3 mi W. Hosford, Rt. 20, 13.vii.1979 (A. Lindsey); 2ƤƤ Liberty Co., Torreya S.P., 25.iii.1986 (B. Alexander); 1Ƥ233 Oklaoosa Co., Rd. 232 at Turkey Creek, 4.x.1966 (P.A. Thomas); 2ƤƤ Taylor Co., 5.x.1960 (F.W. Head); [ CUIC]; 2 ƤƤ Wakulla Co., Apalachicola N.F., Hwy 65, Post Office Bay, N30˚3.565ʹ W084˚59.051ʹ, 29.v–4.vi.2005 (A. Vanderby); 5 ƤƤ Wakulla Co., Apalachicola N.F., Hwy 65, Post Office Bay, N30˚3.565ʹ W084˚59.051ʹ, 13–20.vi.2005 (Ronquist lab); 11 ƤƤ Wakulla Co., Apalachicola N.F., Hwy 65, Post Office Bay, N30˚3.565ʹ W084˚59.057ʹ, 20–27.vi.2005 (Ronquist lab); 6 ƤƤ Wakulla Co., Apalachicola N.F., Hwy 65, Post Office Bay, N30˚3.565ʹ W084˚59.051ʹ, 27.vi–5.vii.2005 (A. Vanderby); 2 ƤƤ Wakulla Co., Apalachicola N.F., FS 366, N30˚19.751ʹ W084˚30.309ʹ, 5–11.vii.2005 (Ronquist lab); 1 ƤƤ Wakulla Co., Apalachicola N.F., FS Road 390, N30˚21.696ʹ W084˚49.399ʹ, 11–18.vii.2005 (Ronquist lab); [ PCYU]; GEORGIA: 1Ƥ Cook Co., Reed Bingham S.P., 29.iii.1974 (G.C. Eickwort); [ CUIC].

Floral records. APIACEAE : Oxypolis filiformis .

DNA Barcode. Available. Multiple sequences. See comments.

Comments. Uncommon.

DNA barcodes do not distinguish L. alachuense from L. oblongum . The two species are closely related but differ by multiple characters of surface sculpture and colour.

Figures

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

FIGURE 47. Lasioglossum alachuense (Mitchell) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 48. Lasioglossum alachuense (Mitchell) female, dorsal view of mesosoma.

FIGURE 49. Lasioglossum alachuense (Mitchell) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 50. Lasioglossum alachuense (Mitchell) male, dorsal view of mesosoma.