Mexalictus (Georgealictus) polybioides Packer, 1993

DUMESH, SHEILA, 2013, <p> <strong> Revision of the rare Mesoamerican bee genus <em> Mexalictus </ em> (Hymenoptera: Halictidae) with the description of </ strong> <br /> <strong> 21 new species </ strong> </ p>, Zootaxa 3708 (1), pp. 1-80 : 70-72

Mexalictus (Georgealictus) polybioides Packer

( Figs. 176–179 )

Mexalictus polybioides Packer, L. 1993 . Can. J. Zool. 71: 1656–1659. Female, male.

Holotype. Male. MEXICO, Chiapas, 20mi N Bochil Yerba Buena , 6500ft. 9-10 June 1969 (WRM Mason) [ CNC].

Diagnosis. Both sexes of this species can be distinguished by the following combination: head and mesosoma non-metallic dark brown; legs golden-hyaline; T2-T5 purple-brown. This species and M. hyalinei are the largest in the genus (10.5–12mm), but M. polybioides can be separated by the non-metallic head and mesosoma (metallic green) and the uniformly-coloured terga (apically yellow-hyaline).

Redescription. Female: Body length 11.2–11.5mm, wing length 10.5mm, head width ITW 1.85–1.90mm. Head: round, L:W = 0.98:1. (1) Labrum and mandible: with subrectangular basal area, flattened basal elevation, narrow triangular distal process. (2) Clypeus: length 0.85X length of supraclypeal area, 2/3 of length below lower ocular tangent, convex in lateral view, not as protuberant supraclypeal area; punctures separated by 1pd basally, coarse and sparse apically (2pd). (3) Supraclypeal area: dull, slightly shiny directly below antennal sockets; strongly convex in lateral view; narrow, width 0.75X length; punctation more or less even throughout, separated by 1–2pd, becoming slightly crowded apico-laterally. (4) Lower paraocular area: mostly dull becoming shiny apicolaterally and towards paraocular lobe; punctation becoming less crowded below antennae, especially towards supraclypeal area (2pd), very finely punctate laterad of paraocular lobe towards inner margin of compound eyes, punctures separated by 2–3pd. (5) Frontal area: punctures dense and crowded, separated by 0.25pd at most; frontal line carinate only between antennae, from basal third of supraclypeal area to 3MOD from median ocellus, with a distinct line reaching median ocellus. (6) Vertexal area: shiny; OOD = 1.8MOD, IOD = 1.7MOD, OVD = 1.2MOD; punctures obscure medially around ocelli, becoming coarse and dense laterally (<1pd). (7) Genal and hypostomal areas: genal area as wide as compound eye in lateral view, shiny with fine punctures separated by 1– 2pd; hypostomal area shiny, bare, and nearly impunctate. (8) Antenna: scape reaching past median ocellus, pedicel slightly longer than wide, F2 shorter than F1, flagellomeres slightly increasing in length from F2–F10, F2–F5 wider than long, F6–F9 quadrate, F10 longer than wide. Mesosoma: (9) Pronotum: smooth with minute punctures, becoming shinier laterally; pronotal lobe pubescent, bearing pale branched hairs. (10) Mesoscutum: dull, appearing granular, especially along margins and median line; densely punctate, punctures separated by 1–2pd in central disc, becoming more crowded basally and laterally past parapsidal line. (11) Mesoscutellum: dull but not as granular as mesoscutum, strongly dull apically; slightly depressed medially with raised areas on central discs appearing slightly bilobed; punctures as on mesoscutum, separated by>1pd in central disc, becoming dense towards margins. (12) Metanotum: somewhat shiny, with shallow sparse punctures, separated by>2pd; with short, yellowish hairs basally. (13) Mesopleuron: granular and sparsely punctate, punctures separated by 4–6pd; pre-episternum weakly granular anteriorly, punctation as mesopleuron; hypoepimeral area and central episternum sparsely punctate (>4pd) above becoming nearly impunctate below. (14) Metapleuron: transversely striate basally, striation weakened, otherwise weakly shiny and impunctate. (15) Metapostnotum and propodeum: metapostnotum dorsally bare, weakly granular, length 0.90X length of mesoscutellum, dorsal striation present basally, normal throughout, extending to apical 1/3; propodeum imbricate laterally, weakly sloping posteriorly. (16) Wings: marginal cell tinted dark brown, venation golden-brown on marginal and basal veins; 1 st recurrent vein meeting 2 nd submarginal cell 1– 1.5 vein widths basad of 2 nd transcubital vein. (17) Tegula: golden-brown, anteriorly dull becoming shiny posteriorly, anteriorly punctate with long pubescence, punctation fine and sparse posteriroly. (18) Foreleg: tarsi with hairs yellowish, basitarsus parallel sided, about 4X as long as width, hairs thick, erect and spine-like with a lateral patch of short pale erect hairs distally; tibia distally broadened, about 2.5X as long as greatest width, with yellow erect hairs, longest ventrally; femur about 3X as long as greatest width, with branched pale yellow sparse hairs ventrally, nearly bare dorsally; trochanter slender, about 2X as long as distal width, with hairs erect; coxa subtriangular, slightly depressed laterally, with branched yellow hairs. (19) Middle leg: as foreleg, except as follows: basitarsus without lateral patch of short hairs distally, short spine-like yellow-brown hairs on inner side and dense yellow hairs on outer side; tibia with apicoventral patch of pale, long and dense pubescence on apical 2/ 3; femur with a lateral patch of dense short golden hairs proximally, and a patch of yellowish long hairs near proximal margin; trochanter distally broadened, length 1.5X width; coxa somewhat hidden within ventral pleuron. (20) Hind leg: as middle leg, except as follows: basitarsus 3.5X as long as greatest width with several branched hairs, pubescence less dense than on tibia; tibia slender, 4X as long as greatest width, densely pubescent, hairs yellow, long and erect; femur 4X as long as greatest width, without lateral patch of hairs, scopa well developed, with long pale yellow branching hairs, somewhat sparse; trochanter and coxa with long, branching, yellow-white pubescence; trochanter much shorter, nearly as long as wide; coxa similar to that of foreleg; tibial spurs translucent yellow, apical 1/3 darkened; inner hind tibial spur microserrate, with over 15 short, close teeth. Metasoma: (21) Terga: T1 shiny brown with a medial yellow band apical margin hyaline, minutely punctate; T2–T5 dull and brown without metallic reflections; pubescence pale, long and branched on T1, short and pale on T2–T4, long and brownish on apical T5, sparse long hairs about 3X as long as short erect hairs. (22) Sterna: S1 with white long pubescence basally, S2–S5 with hairs long and brown, shorter pale hairs along apical margin, S6 with few short and erect brown hairs on apex, otherwise bare.

Male: As in female, except the following: Body length 10.5–10.7mm, wing length 8.5mm, head width 2.18– 2.20mm, ITW 1.43–1.45mm. Head: (1) Labrum and mandible: labrum with a slight medial depression basally, appearing bilobed; distal process extending beyond basal area for up to 0.5X length of labrum, with a row of pale bristles; mandible without subapical tooth, apically reddened. (2) Clypeus: strongly convex, length 0.9X length of supraclypeal area; punctures separated by 1–2pd basally, becoming sparser laterally (2–3pd), apical nearly impunctate. (7) Genal and hypostomal areas: genal area slightly narrower than compound eye in lateral view, about 0.85 X width of compound eye. (8) Antenna: pedicel about as long as wide, first flagellar segment wider than long, longer than segment 2, remaining segments about as wide as long. Mesosoma: (15) Metapostnotum and propodeum: dorsal length of metapostnotum 0.85X length of mesoscutellum; dorsal striation present basally, normal throughout, extending to apical 1/3. Metasoma: (21) Terga: T1 petiolate, much narrowed, pale brown with apical yellow band; T2 with apical area lighter than basal area, faint yellowish. (22) Sterna: S4 with an apical band of dense yellowish hair; S5 with two patches of dense yellow-brown hairs, becoming medially directed centrally. (23) Terminalia: refer to Fig. 23 ( Packer, 1993).

Material examined. MEXICO, Chiapas, 20mi N Bochil Yerba Buena , 6500ft. 9-10 June 1969, WRM Mason [ CNC] (holotype male examined) ; Chiapas, 20mi N Bochil Yerba Buena , 7000ft. cloud for. 10 June 1969. WRM Mason [ CNC] (paratype female examined) .

Figures

FIGURES 176–179. Mexalictus polybioides Packer (1993), 176. Female lateral habitus, 177. Female head 178, Male lateral habitus, 179. Male head. Scale bars = 1mm.

FIGURES 21–24. 21. Mexalictus micheneri Eickwort (1978) female head, longer than wide, 22. M. arizonensis Eickwort (1978) female head, round, 23. M. micheneri female dorsal metapostnotum, striae present, 24. M. astriatus Dumesh, n. sp. dorsal metapostnotum, striae absent. Scale bars = 1mm.