Hexantheda entrerriana Roig­Alsina, 2006

Roig-Alsina, Arturo, 2006, A new species of Hexantheda Ogloblin (Hymenoptera, Colletidae), a genus of bees with labial palpi of variable number of segments, Zootaxa 1229, pp. 33-40 : 34-37

Hexantheda entrerriana Roig­Alsina , new species

Figs. 1–4 , 8, 9

Description

Holotype male. Length 9.5 mm; length of forewing 7.8 mm; head width 3.2 mm.

Color. Black, except reddish apex of mandible, dark reddish brown margin of tegula, tibial spurs, and tarsomeres 2–5 of all legs; T1–T6 with pale, translucent apical impressed areas, impressed area on T2 as broad as MOD. Wings weakly infuscate, veins and pterostigma brown. Pubescence. White, except yellowish brown hairs forming apical fringe of labrum. Pubescence of head dense around antennal socket, laterally on clypeus, and on gena; on paraocular area and clypeus mostly appressed, erect on rest of head; hairs sparse on vertex and underside of head, 1.5–3 times MOD; hair sparse on disc of clypeus, but short, less than MOD. Pubescence of mesosoma long (hairs of mesoscutum 1.5–2 MOD; hairs of mesopleuron 1.5–3 MOD), denser on anterior third of mesoscutum, mesoscutellum, mesopleura, and postero­lateral angles of propodeum. Metapostnotum bare. Pubescence of legs rather sparse, denser on underside of femora and tibiae (hairs under anterior and middle femur as long as 2–2.5 MOD). Metasomal terga with sparse, erect short hairs basally, and with poorly defined apical bands, more conspicuous laterally. S2–S4 basally with long erect hairs (those on S2 as long as 1.5–2 MOD), and apically with poorly defined fringes of short hairs. S5 with well developed fringe of long hairs, lateral ones curved mesially.

Sculpture. Integument of head, mesoscutum, mesoscutellum, and upper part of mesopleuron smooth and shining between punctures; other parts of thorax tessellate among punctures. Clypeus smooth in narrow longitudinal median zone from upper margin to middle of clypeus; rest of disc and supraclypeal area with punctures separated by 0.5–1.5 times their diameter; clypeus laterally with dense, small punctures, corresponding to appressed pubescence. Mesoscutum with anterior and lateral margins closely punctate; punctures becoming more separated towards center of mesoscutum: on anterior third separated by about their diameter and around center of mesoscutum by 2–4 diameters; a small smooth area present behind median mesoscutal line. Disc of mesoscutellum with sparse punctures, median part nearly impunctate. Metanotum roughened, with coalesced punctures. Hypoepimeral area of mesopleuron with smooth lower zone, sparse punctures above, and dense punctures close to upper and posterior margins; mesepisternal groove bearing deep transverse punctures; rest of mesopleuron with small punctures separated by 1–3 diameters. Metapostnotum with basal horizontal part bearing weak transverse wrinkles and posterior part minutely tessellate; lateral and posterior sides of propodeum tessellate. Metasomal terga dull, minutely and densely shagreened, with scattered punctures; metasomal sterna also shagreened.

Structure. Inner orbits weakly concave, upper and lower interocular distances equal. Ocellocular distance greater (1.2 times) than interocellar distance. Vertex behind ocelli elevated; distance between lateral ocellus and posterior margin of head 2.0 MOD. Gena tapering below and much swollen above, with maximum width at level of upper fifth of eye, and as wide as maximum eye width. Clypeus protuberant in lateral view, for a distance 0.72 times maximum eye width. Antennocular distance greater (1.2 times) than interantennal distance. Clypeus 2.5 times as wide as long; apical margin bearing fringe of stiff setae, depressed, forming weak preapical carina. Labrum 4.25 times as wide as long, with median depression. Mandible broadened proximad to preapical tooth ( Fig. 4 ). Labial palpus 8­segmented, 0.9 times as long as prementum; relative lengths of segments, 1.2:1:0.9:0.8:0.6:0.4:0.25:0.6. Antennal scape reaching lateral ocellus, shorter (0.75 times) than distance from upper margin of clypeus to median ocellus. First flagellomere longer (1.15 times) than its apical width, second and third about 0.85 times as long as their apical width. Wing venation entirely similar to that of H. missionica . Basitibial plate with pointed apex. T7 without defined pygidial plate, densely hairy laterally and with bare, convex, longitudinally ovate area. S6 narrowly notched at apex. S7 on each side with two well developed apicolateral lobes bearing rows of peg­like setae; basal lobe not divided in two ( Fig. 8 ). S8 truncate apically ( Fig. 9 ). Genital capsule as in H. missionica .

Female. Length 9.2 mm; length of forewing 6.7 mm; head width 2.6 mm. As in male except for usual secondary sexual characteristics, and as follows: Color, pubescence and sculpture similar to those of male, except as follows. T1–4 with pale, yellowish, translucent apical bands. Pubescence white on head, thorax, base of legs, propodeum, and most of metasoma; brown on apex of femora, tibiae and tarsi, except white hairs under hind tibia; prepygidial fimbria brown, and pygidial fimbria dark brown. Hairs of mesoscutum 1–1.5 MOD; hairs of mesopleuron 1.5–2 MOD. Structure. Ocellocular distance subequal (1.05 times) to interocellar distance. Vertex behind ocelli elevated, but not as much as that of male; distance between lateral ocellus and posterior margin of head 1.2 MOD. Clypeus twice as wide as long; clypeus protuberant in lateral view, for a distance 0.7 times maximum eye width. Antennocular distance greater (1.12 times) than interantennal distance. Antennal scape barely reaching median ocellus, shorter (0.7 times) than distance from upper margin of clypeus to median ocellus. First flagellomere as long as its apical width, second and third about 0.85 times as long as their apical width. Tibial scopa with hairs on outer surface 1.7–2.5 times MOD, with one to three long branches directed apicad, and arising beyond proximal third to half of rachis. S2–S5 with well developed metasomal scopa; scopal hairs on S2 mostly simple, three times MOD.

Etymology

The name entrerriana comes from spanish, meaning “native from Entre Ríos.”

Material studied

Argentina, province of Entre Ríos: holotype male, Liebig, 15–XII–2004, on Petunia sp., A. Roig Alsina ( MACN); paratype male, same data as holotype ( MACN); paratype female, Palmar Colón, XII–1975, M. Fritz ( MACN).

Figures

FIGURES 1 – 7. H. entrerriana, paratype male: 1, head, frontal view; 2, antenna; 3, head, lateral view; 4, mandible. H. missionica: 5, head, frontal view; 6, antenna; 7, mandible. Scale lines = 1 mm.

FIGURES 8 – 9. H. entrerriana, paratype male: 8, seventh metasomal sternum; 9, eighth metasomal sternum. Scale line = 1 mm.