Megalopta (Megalopta) guimaraesi, Santos, Leandro M. & Silveira, Fernando A., 2009

Santos, Leandro M. & Silveira, Fernando A., 2009, Taxonomic notes on Megalopta Smith, 1853 (Hymenoptera: Halictidae: Augochlorini) with a synopsis of the species in the state of Minas Gerais, Brazil, Zootaxa 2194, pp. 1-20 : 10-12

Megalopta (Megalopta) guimaraesi sp. n.

( Figs. 1, 5, 10, 12, 15)

Diagnosis. Ƥ/3: Body length 10.5–12.6 mm. Lateral surface of metaposnotum polished, sometimes with minute punctures, its posterior margin, medially, almost parallel to anterior margin, bending abruptly laterally, towards metanotum; disc of scutellum flat, gently slanting to rear, its posterior margin below level of metanotum; dorsal surface of axilla and contiguous antero-lateral margin of scutellum on same plane as disc of scutellum; metapostnotum homogeneously metallic green, with a single, distinct, mid longitudinal ruga, flanked by one or two weaker ones as long as or longer than metanotum, its pubescence of metepisternum densely plumose, entirely hiding its surface; metepisternal process conspicuous, wide (extremely wide on male), covered by velvety pilosity.

3: Disc of S3 with mid-longitudinal depression shallow and narrow throughout most its length, widening abruptly as it approaches the marginal zone of sternum; marginal lobes of S3 long, well separate from each other; protruding process of S4 trapezoidal, with a brush of relatively long setae apically.

Description. Female holotype.

Measurements: Intertegular distance: 3.84 mm; width of head: 3.84 mm; total body length: 12.5 mm.

Color: Metallic green on head and mesosoma, with golden-red hues on clypeus, supraclypeal and paraocular areas, vertex and mesoscutum; ferruginous on mandible (except black apical margin), labrum, lower margin of paraocular area, antenna, pronotum, axila, lateral areas of metanotum, tegula, pterostigma and veins (except blackish Sc+R), legs, T1, T2 basally and all sterna; whitish-ferruginous on apical margin of clypeus; brownish to blackish-ferruginous on apical half of T2 and remaining terga.

Pilosity: White, except light yellow on mandible, labrum, apical fringe of clypeus, simple erect hairs of clypeus, lower paraocular and supraclypeal areas and on tarsi. Relatively thick, simple and long on apical margin of clypeus, ventral margin of mandible, hypostomal area, posterior margins of anterior trochanter and femur; dense, long, relatively fine and finely branched, suggesting a sternal scopa, on discs of S1–S4, thicker and simple laterally and on S5; relatively long and erect on face, and on vertex, gena and disc of mesoscutum (on latter three, intermixed with short, very fine, minutely-branched decumbent hairs); longer and branched on anterior margin of mesoscutum, discs of scutellum and metanotum and lateral surface of mesepisternum; longer on ventral surface of mesepisternum, lateral surface of propodeum and ventral surfaces of trochanters, femora and tibiae; simple and very fine on disc of T2–T6 and marginal zones of T1–T6, minute on T1, progressively longer toward T6. Sparsely tomentose, intermixed with erect hairs, on frons, paraocular area, mesoscutum (denser on antero-lateral corner and on lateral margin especially posteriorly), scutellum, metanotum, mesepisternum, lateral and posterior surfaces of propodeum and on anterior coxa; densely tomentose, hiding the integument, on lateral surface of pronotum (partially), metepisternum and antero-lateral corner of propodeum, at base of metepisternal process. Composed of thick bristles on outer surfaces of tibiae and tarsi, longer on hind leg; forming a comb on inner surface of mid tibia. Scopa present on hind femur.

Surface: Clypeus sparsely punctate apically, denser basally, punctures moderately coarse and fine intermixed; supraclypeal area sparsely punctate apically, densely punctate laterally and very dense basally, leaving an ill-defined impunctate area on disc, punctures coarse apically, very fine close to antennal sockets; lower paraocular areas coarsely and densely punctate, except for polished band along lateral section of epistomal suture; upper paraocular area and frons moderately fine and very densely punctate, the space between punctures cariniform, surface microreticulate on upper paraocular area, on eye margin; punctures on vertex, fine and dense, very fine and progressively sparse toward area between and behind lateral ocellus and eye; gena, minutely and sparsely punctate, punctures dense along posterior eye margin; hypostomal area, very finely and very sparsely punctate, the surface shiny microreticulate; pronotum coarsely rugose laterally, smooth dorsally, minutely punctate ventrad, surface shiny; mesoscutum with fine and dense punctures, denser toward the antero-lateral corners and lateral margins, with moderately coarse punctures intermixed on mid portions and leaving a large ill-defined, very sparsely punctate area on posterior half, surface lightly microreticulate anteriorly, polished posteriorly; scutellum sparsely punctate, the punctures very fine with few fine ones intermixed, surface polished; metanotum sparsely punctate, the punctures minute with fine ones intermixed, its surface polished; basal area of metapostnotum, with a mixture of fine and minute punctures, relatively sparse, its surface polished; mesepisternum with a granular appearance; preomaular area coarsely punctate, punctures relatively sparse and beveled, the surface shiny microreticulate; omaular area and ventral portion of mesepisternum coarsely reticulate, punctures moderately coarse, beveled, relatively sparse; hypoepimeral area with a sparse mixture of minute and moderately fine punctures, surface polished; lateral area of propodeum shiny reticulate, punctures relatively coarse, relatively dense; disc of T1 very weakly microreticulate, shiny and impunctate, anterior and lateral surfaces very sparsely and very finely punctate, marginal zone sparsely and minutely punctate; T2 sparsely and minutely punctate on disc, very finely punctate laterally, punctation denser on marginal zone, surface shiny microreticulate; punctures slightly coarser and denser on T3–T6; on sterna, punctures sparse, fine and verrucose, the surface shiny microreticulate.

Structure: Basal tubercle of labrum gently bituberculate; eyes slightly diverging below, strongly converging above, subparallel elsewhere; frontal line carinate, carina ending one ocellar diameter bellow anterior ocellus; vertex much elevated above lateral ocelli, its height more than one ocellar diameter above dorsal margin of lateral ocelli in frontal view; gena wider than eye in lateral view (see comments below); hypostomal carina much developed, bifid anteriorly; dorso-lateral corner of pronotum angulate (90º), in frontal view; metepisternal process wide; scutellum flat, gently slanting posteriorly, its posterior margin below level of metanotum; dorsal surface of axilla and contiguous antero-lateral margin of scutellum in same plane as disc of scutellum; posterior margin of metapostnotum gently curved, almost parallel to the anterior margin; metapostnotum with a single ill-defined longitudinal ruga.

Allotype (male). Color: Metalic green with brassy hues on supraclypeal and paraocular areas, front, vertex, gena, mesoscutum, scutellum, metanotum, metapostnotum, lateral and ventral areas of mesepisternum and on propodeum; ferruginous with metalic-green tints on basal half of clypeus; whitish ferruginous on labral base, mandible base and apical band of clypeus; blackish brown on dorsal surface of F6–F11 (except brownish ferruginous apically on F11), marginal depressions of T3–T4 and vein Sc+R on anterior wing; brownish on marginal zones of T1–T2; light ferruginous elsewhere.

Pilosity: light yellow except white tomentose pilosity on face, gena, pronotum, mesoscutum, mesepisternum, metepisternum and propodeum and white erect hairs on ventral surfaces of mesosoma, including coxae. Distribution, length and diameter similar to that on female, except for tomentum generally denser and for a brush of thick decumbent setae on apical lobes of S3, a dense apical brush on digitiform process of S4 (hidden under S 3 in this specimen, seen in a paratype from Caldas Novas, state of Goiás) and a submarginal band of erect, thick, hooked setae around each apical lobe of S4.

Surface: Similar to female; on T1–T2, densely microreticulate on disc, shiny microreticulate with polished, ill-defined areas on marginal zones; T3 entirely shiny microreticulate; punctures sparser than on female on terga.

Structure: Similar to female but face much narrower, eyes strongly converging below, distance between eye and upper corner of clypeus, in frontal view, less than basal diameter of scape; mid-longitudinal depression of S3 shallow and narrow throughout most its length, widening abruptly as it approaches marginal zone of sternum, not defining discal lobes; marginal lobes of S3 long, well separate from each other; protruding process of S4 trapezoidal, with apical brush of relatively long setae; marginal notch of S5 relatively narrow; mid-longitudinal ridge of S6 carinate, deeply fended.

Type material. Holotype (female): “Serra do Cipó 3009-8889”; “ Jaboticatubas MG BRASIL 25/03/1998 D.A..Yanega” and “ HOLOTYPUS Megalopta (Megalopta) guimaraesi Ƥ Santos & Silveira sp. nov ”. Deposited in UFMG. Macrocephalic female.

Allotype (male): “Fazenda Mandioca, 12801-37804”; “Conquista MG, Brasil 16/01/1989, P.A.R. Machado”. Deposited in UFMG.

Paratypes: BRAZIL, BAHIA. Camacã, Serra Bonita, 800m, 15º 23’S 39° 34’W, 14/01/2007 [G.Melo] (2Ƥ Ƥ){DZUP}. Rio de Contas, 900m, 25-30/01/2007 [Mielke & Casagrande leg] (1 Ƥ){DZUP}. DISTRITO FEDERAL. Brasília, 1000m, 15/09/1984 [V.O.Becker] (1 Ƥ){DZUP}. Planaltina, 15º 35’S 47º 42’W, 18/09/ 1984 [V.O.Becker] (4Ƥ Ƥ){DZUP}; 25/09/1985 [V.O.Becker] (2Ƥ Ƥ){DZUP}. GOIÁS. Caldas Novas, Parque Estadual da Serra de Caldas Novas, 19/10/2007 13079-38793 [Augusto, S.C.] (1 Ƥ), idem (13) {UFMG}; 20/10/2007, 13080-38795 [Augusto, S.C.] (1 Ƥ) {UFMG}; 22-23/03/2008, 17°46’13”S 48°39’22”W, arm. luz [J.A.Rafael, F.F.Xavier F°] (2Ƥ Ƥ) {DZUP}. Chapada dos Veadeiros, Vale Dourado, 14º11’S 47º37’W, 1200m, 31/03/2003 [Melo,Aguiar, Marchi & Gonçalves] (13); 01/04/2003 14º 11’S 47º 37’W, 1100m [idem] (5Ƥ Ƥ,){DZUP}. Formosa, 800 m, 22/09/1984 [V.O.Becker]{DZUP}. MINAS GERAIS. Bocaiúva, 05/11/1998 [Azevedo & Silveira]; Abelhas Cerrado - Mannesman, Faz. Corredor, 2675-7992 (1Ƥ), idem, 2675-7993 (1Ƥ), idem 2675-7994 (1Ƥ without head) {UFMG}. Corinto, 16-31/11/1979 [C Elias leg] (13) {DZUP}. Marliéria, Parque Estadual do Rio Doce, 20-26/10/1980 [R.S.Monteiro & C.S.Mascarenhas] (2ƤƤ) {UFMG}. Morro da Garça, 18-20/10/1964. Exp. Dep. Zool. (3ƤƤ) {MZUSP}. Paracatu, 17/02/ 2008, Licenciamento AHE Batalha, Faz. Jomar, 13081-38798 [E.L.Siqueira] (1Ƥ) {UFMG}. São Gonçalo do Rio Abaixo, EPDA de PETI, 23/02/2005 [R.B.Martines] (1Ƥ) {UFMG}. Três Marias, Ilha de Três Marias, 5185-14248, 31 /11/1997 [D.A.Yanega] (1Ƥ) {UFMG}. Viçosa, Córrego do Paraíso, Mata da Prefeitura, 08/ 01/1988 [P.S.Fiuza F.] (1Ƥ) {MEUV}. RIO DE JANEIRO. Rio de Janeiro, Floresta da Tijuca, 05/03/1960 [C.A.C. Seabra] (1Ƥ) {DZUP}. SÃO PAULO. Alvinlândia, Estação Ecológica Caetetus, 22º 23’S 49º 49’W, 07-08/12/1999 [F.C.Passos] (1Ƥ) {DZUP}. Bauru, 03/12/1997 [F.Knoll] (1Ƥ); 11/12/1997 [F.Knoll] (2 ƤƤ); 18/02/1998 [F.Knoll] (1Ƥ); 16/09/1998 [F.Nomura] (3ƤƤ); 27/10/1998 [R.Marono] (3ƤƤ); 03/11/1998 [F.Nomura] (1Ƥ); 04/12/1998 [R.Marono] (2ƤƤ); 15/03/1999 [R.Marono] (1Ƥ); 20/04/1999 [R.Marono] (1Ƥ) {UFMG}. Luis Antônio, Reserva Jataí, 06/04/1994 [M.C.Ganlianone] 1(Ƥ) {RPSP}.

Distribution. BRAZIL (BAHIA, DISTRITO FEDRAL, GOIÁS, MINAS GERAIS, RIO DE JANEIRO AND SÃO PAULO).

Etymology. This species is named in memory of the Brazilian writer João Guimarães Rosa, born in Cordisburgo, Minas Gerais, after the 40th anniversary of his death.

Comments. The weak divergence of the eyes below, the wide gena and the much-elevated vertex of the holotype are features of macrocephalic females, and are not found in normal specimens. Some specimens have more than one longitudinal ruga on the metapostnotum. The mesoscutum, scutellum and metanotum of some specimens are polished black.

Megalopta guimaraesi can be easily distinguished from M. amoena by the wide metepisternal process, which is covered by velvety pilosity (normal, inconspicuous, without special pilosity in M. amoena ) and by the homogeneously metallic green metapostnotum (without green metallic reflections in M. amoena ). It can be distinguished from M. aegis and M. sodalis by the polished lateral surface of metapostnotum (reticulate in M. aegis and M. sodalis ) and the flat scutellum (gently convex in M. aegis and M. sodalis ). It differs from M. sulciventris Friese, 1926 in its flat scutellum (convex in M. sulciventris ), for the wide metepisternal process (normal, inconspicuous in M. sulciventris ) and its single, distinct longitudinal rugae, sometimes flanked by one or two weaker ones in the central area of metapostnotum (several equally-strong rugae extending laterally in M. sulciventris ).

The 15 specimens from Bauru in the type series were attracted to eucalyptol, eugenol and methyl salicylate; other specimens from the same locality were attracted to benzyl acetate, skatole and vanilin. Specimens collected with eugenol are frequently darker, probably because they soak themselves with this dark, oily substance.