Lasioglossum (Dialictus) flaveriae (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 89-92

Lasioglossum (Dialictus) flaveriae (Mitchell)

( Figures 98–101 )

Dialictus flaveriae Mitchell, 1960: 393 . Ƥ 3.

Holotype. Ƥ USA, Florida, Dade Co., Everglades Nat. Pk., 10.iii.1955 on Flaveria linearis (H.A. Denmark) ; [ FSCA]. Examined.

Dialictus tahitensis Mitchell, 1960: 421 . Ƥ. [new synonymy]

Holotype. Ƥ USA, Florida, Dade Co., Tahiti Beach, 29.v.1927 (S. Graenicher); [ NCSU]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) flaveriae , p. 463, L. (D) tahitense, p. 466 (catalogue); Moure and Hurd, 1987: Dialictus flaveriae , p. 100, D. tahitensis , p. 132 (catalogue).

Diagnosis. Both sexes of L. flaveriae can be recognised by the following diagnostic combination: metapostnotum smooth, rugae not extending more than halfway to posterior margin ( Figs. 99 , 101 ); mesepisternal punctures deep and distinct; gena narrower than eye; and lower paraocular area with sparse tomentum. Males can also be recognized by the elongate S5–S6 hairs visible as two posteriorly directed tufts in dorsal view. They are most similar to the Caribbean species L. gundlachii ( Baker) which has the surface of the mesoscutum and mesepisternum duller due to microsculpture.

Redescription. FEMALE. Length 4.11–4.66 mm; head length 1.16–1.25 mm; head width 1.18–1.32 mm; forewing length 2.78–3.27 mm.

Colouration. Head and mesosoma pale green to blue. Clypeus with apical half blackish brown. Antenna dark brown, flagellum with ventral surface brownish yellow. Tegula reddish brown. Wing membrane subhyaline, venation and pterostigma yellowish brown. Legs brown except tarsi, and apical and basal portions of tibiae brownish yellow. Metasoma reddish 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 apical fringes.

Surface sculpture. Face imbricate, punctation very fine. Clypeus with apical half polished, punctation moderately sparse apically (i=1–2d), denser basally (i≤d). Supraclypeal area with punctation moderately sparse (i=1–2d), denser laterally. Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i=1–1.5d). Upper paraocular area and frons very finely punctate. Ocellocular area punctate (i=1–1.5d). Gena lineolate. Postgena imbricate. Mesoscutum weakly imbricate, polished submedially, 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-punctate (i=1–1.5d). Mesepisternum weakly imbricate, distinctly punctate (i=1–2d). Metepisternum with upper half carinulate and ventral portion imbricate. Metapostnotum with short rugae not extending halfway to posterior margin, posterior margin weakly imbricate. Propodeum with dorsolateral slope imbricate, lateral and posterior surfaces tessellate-imbricate. Metasomal terga polished, punctation moderately sparse basally (i=1–2d), more widely spaced apically (i=1–2.5d), T2 apical impressed area impunctate.

Structure. Head moderately wide (length/width ratio = 0.95–0.99). Eyes convergent below (UOD/LOD ratio = 1.27– 1.30). Clypeus 1/2–2/3 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 3–4 branches. Metapostnotum moderately elongate (MMR ratio = 1.10–1.20), posterior margin 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 3.63–3.93 mm; head length 1.25–1.28 mm; head width 1.22–1.26 mm; forewing length 3.15–3.21 mm.

Colouration. Flagellum with ventral surface reddish brown. Legs brown, except tibial bases and apices, and tarsi brownish yellow, pro- and mesotibiae sometimes infused with brownish yellow.

Pubescence. S2–S4 apical halves with moderately dense hairs (1.5 OD), S5–S6 lateral portions with medially directed elongate hairs (3–4 OD).

Surface sculpture. Punctation coarser. Metasomal terga with apical impressed areas impunctate.

Structure. Head moderately elongate (length/width ratio = 1.02). Eyes strongly convergent below (UOD/LOD ratio = 1.45–1.48). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets distant (IAD/OAD> 1.1). Frontal line carinate, ending 2 OD below median ocellus. Pedicel subequal to F1. F2 length 1.3–1.4X F1. F2–F10 short (length/width ratio = 1.15–1.30). Metapostnotum moderately elongate (MMR ratio = 1.20), posterior margin rounded onto posterior surface. Propodeum with oblique carina absent.

Terminalia . Gonostylus posteriorly directed, very long setae emerging from base. Retrorse lobe short.

Range. Bahamas, Florida ( Fig. 102 ).

Additional material examined. BAHAMAS: Gorda Cay, N26°05ʹ W77°32ʹ, 14–20.vi.1998 (S. Glasscock); [ UCFC]; USA: FLORIDA: 2ƤƤ Flamingo, Everglades N.P., 1–5.xii.1961 (Munroe, Holland & Chillcott); [ CNC]; 1Ƥ paratype Dade Co., Everglades Nat. Pk., 10.iii.1955 (H.A. Denmark); 1Ƥ paratype Dade Co., Everglades Nat. Pk., 11.iii.1955 (H.A. Denmark); 233 paratype s Cape Sable, Everglades N.P., 25.iii.1954 on salt flats (K.V. Krombein); 3ƤƤ paratypes Paradise Key, 6.iv.1951 (H. & M. Townes); [ CUIC]; 1Ƥ Mahogany Hammock, Everglades N.P., 4.xii.1970 (J. Powell); [ EMEC];13 allotype, Dade Co., Everglades Nat. Pk., 17.iii.1955 on Lyonia mariana (H.A. Denmark) ; [ FSCA]; 13 paratype Cape Sable, Everglades N.P., 25.iii.1954 on salt flats (K.V. Krombein); 4ƤƤ paratypes Dade Co., Everglades Nat. Pk., 11.iii.1955 (H.A. Denmark); 1Ƥ paratype Matheson Hammock, 8.iv.1955 (T.B. Mitchell); 3ƤƤ paratypes Paradise Key, 6.iv.1951 (H. & M. Townes); [ NCSU]; 1Ƥ paratype, Cape Sable, Everglades N.P., 25.iii.1954 on salt flats (K.V. Krombein); 13 paratype, Paradise Key, Everglades N.P., 22.iii.1954 (K.V. Krombein); [ NMNH]; 1Ƥ Lee Co., N26.4479 W082.0407, 5.vi.2007 (S.W. Droege); 1Ƥ Lee Co., N26.4419 W082.0803, 5.vi.2007 (S.W. Droege); 1Ƥ Martin Co., N27.0863 W080.1248, 4.vi.2007 (S.W. Droege); [ PCYU].

Floral records. AMARANTHACEAE : Achyranthes “mercantifolia”; ASTERACEAE : Flaveria linearis , Mikania , Sartwellia flaveriae ; ERICACEAE : Lyonia mariana .

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon.

The holotype specimens of Dialictus flaveriae and D. tahitensis differ only in size and colouration. Neither of these characters is reliable for delimiting Dialictus species and colour is often affected by preservation. Both holotypes have brownish orange metasomata but this might be an artefact. Paratypes and recently collected material have the metasoma reddish brown.

The West Indian species L. gundlachii is very similar to L. flaveriae both morphologically and based on DNA barcodes. Several Floridian species also occur in Cuba and islands of the West Indies (e. g. L. eleutherense discussed above and L. halophitum below). Jamaican specimens of L. gundlachii were found to have more microsculpture on the mesosoma than does L. flaveriae . These two species show affinities to mainland Neotropical species (see Danforth et al. 2003).

Figures

FIGURE 98. Lasioglossum flaveriae (Mitchell) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 99. Lasioglossum flaveriae (Mitchell) female, dorsal view of mesosoma.

FIGURE 100. Lasioglossum flaveriae (Mitchell) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 101. Lasioglossum flaveriae (Mitchell) male, dorsal view of mesosoma.

FIGURE 102. Distribution map of Lasioglossum flaveriae (stars) and L. floridanum (circles).