Lasioglossum (Dialictus) miniatulum (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 145-147

Lasioglossum (Dialictus) miniatulum (Mitchell)

( Figures 160–163 )

Dialictus miniatulus Mitchell, 1960: 405 . Ƥ.

Holotype. Ƥ USA, Florida, Jacksonville Beach, 5.viii.1946 [ NCSU]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) miniatulum , p. 464 (catalogue); Hurd, 1979: Dialictus miniatulus , p. 1968 (catalogue); Moure and Hurd, 1987: Dialictus miniatulus , p. 113 (catalogue)

Diagnosis. Female L. miniatulum can be recognised by the following diagnostic combination: head and mesosoma bluish; head wide to round (length/width ratio = 0.96–0.99); postgena lineolate; mesoscutal punctures dense throughout (i<d) ( Fig. 161); mesepisternum punctate; T1 acarinarial fan without dorsal opening; and metasomal terga brown, T3 with moderately dense tomentum ( Fig. 160 A). They are superficially similar to L. perpunctatum , which has head and mesosoma greenish, postgena glabrate, and dense tomentum on T3.

Male L. miniatulum can be recognised by the following diagnostic combination: head round (length/width ratio = 1.00) ( Fig. 162 B); pronotal ridge broadly rounded; parapsidal line narrow ( Fig. 163 ); mesepisternum with punctation distinct, dense; tegula ovoid; tarsi brownish yellow; metasomal terga brown, except posterior margins reddish; T2–T3 without tomentum; T2 apical impressed area distinctly punctate; and sternal pubescence short (1OD). They are most similar to L. arantium which have sparse basolateral tomentum on T2–T3 and have pale green mesoscutal integument.

Redescription. FEMALE. Length 4.41–5.02 mm; head length 1.32 mm; head width 1.37 mm; forewing length 3.09–3.33 mm.

Colouration. Head and mesosoma pale blue. Labrum and mandible reddish brown to yellow. Clypeus with apical half blackish brown. Antenna dark brown, flagellum with ventral surface brown to reddish brown. Tegula pale yellow. Wing membrane subhyaline, venation and pterostigma yellowish brown. Legs brown, except tibial bases and apices, medio- and distitarsi, and sometimes protibia and basitarsi reddish to brownish yellow. Metasoma terga blackish brown, T1–T2 with some reddish tints anteriorly, terga and sterna with apical margins translucent yellow.

Pubescence. Dull white. Moderately dense. 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 subappressed tomentum, not obscuring surface. Mesoscutum lateral margins and mesepisternum dorsally with tomentum. Metepisternum obscured by tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with moderately dense, fine hairs. T1 acarinarial fan complete (obscure on pale background). T1 apicolaterally, T2–T3 basally and laterally, and T4 throughout with moderately dense tomentum partially obscuring surface. T2 apicolateral and T3–T4 apical margins with relatively dense fringes.

Surface sculpture. Face imbricate, punctation moderately strong. Clypeus with apical half polished, punctation moderately sparse (i=1–1.5d). Supraclypeal area with punctation moderately sparse (i=1–1.5d). Lower paraocular area and antennocular area punctation dense (i≤d). Upper paraocular area, frons and ocellocular area punctate-reticulate. Gena and postgena lineolate. Mesoscutum weakly imbricate, polished submedially, punctation dense between parapsidal lines (i≤d), contiguous laterad of parapsidal line and punctate-reticulate on anterolateral portion. Mesoscutellum polished, submedial punctation sparse (i=1–2d). Axilla punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area imbricate-punctate. Mesepisternum rugulose-punctate (i≤d), smoother below. Metepisternum with dorsal half rugosocarinulate, ventral half imbricate. Metapostnotum with anastomosing rugae nearly reaching posterior margin. Propodeum with dorsolateral slope and lateral surface rugulose-imbricate, posterior surface tessellate. Metasomal terga polished, punctation distinct throughout, close on basal halves (i=1–1.5d), more widely spaced on marginal zone (i=1–2d).

Structure. Head wide (length/width ratio = 0.96–0.99). Eyes convergent below (UOD/LOD ratio = 1.25–1.27). Clypeus 1/2 below suborbital tangent, apicolateral margins strongly 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 3–4 branches. Metapostnotum moderately elongate (MMR ratio = 1.19–1.35), posterior margin rounded onto posterior surface. Propodeum with oblique carina obscure, lateral carina weak, not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 3.90 mm; head length 1.13 mm; head width 1.13 mm; forewing length 2.81 mm.

Colouration. Mandible yellow on apical half. Flagellum with ventral surface reddish brown. Pterostigma yellowish brown. Legs brown, except bases and apices of tibiae, and tarsi brownish yellow. Metasomal terga brown, apical impressed areas reddish brown.

Pubescence. Face below eye emargination with scattered tomentum partially obscuring surface, dense on lower paraocular area.

Surface sculpture. Mesoscutal punctation between parapsidal line relatively sparse (i=1–1.5d). Mesepisternum distinctly punctate

Structure. Head wide (length/width ratio = 1.00). Eyes strongly convergent below (UOD/LOD ratio = 1.71). Clypeus 1/2 below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets distant (IAD/OAD> 1.4). Frontal line carinate, ending 1.5 OD below median ocellus. Pedicel shorter than F1. F2 length 1.6X F1. F2–F10 moderately elongate (length/width ratio = 1.44–1.67). Metapostnotum elongate (MMR ratio = 1.22), posterior margin rounded onto posterior propodeal surface.

Terminalia . Not examined.

Range. Coastal areas of Florida ( Fig. 159 ).

Additional material examined. USA: FLORIDA: 2ƤƤ paratypes Jacksonville Beach, 5.viii.1936 (T.B. Mitchell); 1Ƥ paratype Jacksonville Beach, 20.viii.1937 (T.B. Mitchell); [ CUIC]; 1Ƥ paratype Jacksonville Beach, 5.viii.1936 (T.B. Mitchell); [ NMNH]; 25ƤƤ Martin Co., N27.0072 W080.1015, 4.vi.2007 (S.W. Droege); 7ƤƤ Martin Co., N27.0125 W080.1028, 4.vi.2007 (S.W. Droege); [ PCYU]; 3ƤƤ Highland Co., Lake Placid, Archbold Biol. Stn., 8–14.ix.1987 ( BRC Hym. Team); 2ƤƤ Highland Co., Lake Placid, Archbold Biol. Stn., 15–21.ix.1987 ( BRC Hym. Team); [ CNC]; 1Ƥ Orange Co., Orlando, 12.ix.1992 (S.M. Fullerton); 2ƤƤ Orange Co., Orlando, 19.x.1993 (S.M. Fullerton); [ UCFC].

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon. For additional comments see L. arantium (above).

Figures

FIGURE 159. Distribution map of Lasioglossum marinum (circles) and L. miniatulum (stars).

FIGURE 160. Lasioglossum miniatulum (Mitchell) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 162. Lasioglossum miniatulum (Mitchell) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 163. Lasioglossum miniatulum (Mitchell) male, dorsal view of mesosoma.