Mexalictus (Mexalictus) gibbsi Dumesh, 2013

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 : 29-31

Mexalictus (Mexalictus) gibbsi Dumesh , new species

( Figs. 110–111 )

Holotype. Female. MEXICO, Michoacan, Quiroga , 7-15-56, R & K Dreisbach [ CUIC].

Diagnosis. This species can be distinguished by the following combination: clypeus, mesoscutum, and mesoscutellum with fine and dense punctures; inner hind tibial spur with less than 8 long teeth, separated by tooth width; metapostnotum with very short striae, dorsal surface strongly imbricate. This species is most similar to M. micheneri , M. astriatus , and M. punctatus , but differs by the round head (head longer than wide in M. micheneri and M. astriatus ), and the strongly curved inner hind tibial spur (nearly straight in M. punctatus ).

Description. Female (Holotype): Body length 7.7mm, wing length 5.5mm, head width 1.63mm, ITW 1.15mm. Head metallic green, mesosoma green. Head: round, L:W = 1.06:1. (1) Labrum and mandible: labrum with subrectangular basal area, medial length 0.33X width, basal elevation flattened, apicomedian area elevated, distal process narrow triangular; mandible dark brown basally, becoming red apically. (2) Clypeus: shiny, about third apical surface brown, metallic green above; length shorter than length of supraclypeal area (0.82X), 0.6 of length below lower ocular tangent, weakly convex in lateral view, less protuberant than supraclypeal area; punctures separated by 1.5–2pd throughout basal green 2/3 of clypeal area, becoming slightly more crowded laterally, punctures on apical area larger and scattered. (3) Supraclypeal area: shiny, slightly dulled mesad of antennal sockets; convex, slightly protuberant, about 0.92X as wide as long, greatest width subequal to length from upper clypeal margin to lower margin of antennal sockets; punctures separated by 1–1.5pd laterally, becoming sparser medially and apically. (4) Lower paraocular area: shiny, becoming weakly imbricate towards antennal socket; punctures separated by <1pd, becoming slightly sparser laterad of supraclypeal area, finer along inner ocular margin (1–2pd), punctures fine and well separated towards paraocular lobe; paraocular lobe very sparsely and finely punctate. (5) Frontal area: frontal line carinate between antennae, reaching 2MOD in front of median ocellus; compound eye more convex below than above; punctation coarse and crowded above antennae. (6) Vertexal area: shiny, with weak transverse depression; IOD = 2.0MOD, OOD = 1.9MOD, OVD = 1.1MOD; larger punctures separated by 2–3pd, smaller punctures by 1–2pd. (7) Genal and hypostomal areas: genal area subequal in width to compound eye in lateral view, shiny with fine punctures separated by 3–4pd above, denser below (1–2pd), hypostomal area with very sparse punctures, separated by>5pd. (8) Antenna: dark brown, scape, pedicel, and F1– F3 darker than F4–F10; scape reaching posterior margin of median ocellus, pedicel and F1 slightly longer than wide, F2 and F3 subequal, both slightly wider than long and shorter than F1, F2 to F10 slightly increasing in length apically, F10 longer than wide. Mesosoma: (9) Pronotum: smooth, nearly impunctate, very minutely imbricate; posterodorsal margin of pronotum with complete band of hairs, including pronotal lobe which is densely outlined. (10) Mesoscutum: nearly entirely shiny, with minute imbrication anteriorly; punctures of 2 sizes, larger punctures separated by>4pd, smaller punctures separated by 1–2pd. (11) Mesoscutellum: entirely shiny, with a median impressed line on basal half; punctation similar to that of mesoscutum. (12) Metanotum: slightly dull due to imbrication; large punctures similar to those of mesoscutum and mesoscutellum, small punctures much smaller and finer, separated by ~2pd. (13) Mesopleuron: shiny and polished above imbricate below; punctures of 2 sizes, larger punctures sparse, mostly separated by>6pd, but posteriorly denser (~3pd), smaller punctures very fine, separated by 2–4pd; pre-episternum imbricate and dull, punctation denser and coarser above, similar to that of mesopleuron below; hypoepimeral area and disc of episternum smooth, shiny and very finely and sparsely punctate. (14) Metapleuron: dull, becoming slightly shiny on lower 1/4, basal transverse striation strong on upper 1/3. (15) Metapostnotum and propodeum: dorsal length of metapostnotum slightly longer than posterior width, posterior margin rounded, dorsally bare, entirely imbricate, imbrication strongest basally, minutely alveolate on basal half, strongly striate basally across entire width, extending to apical; propodeum impunctate posteriorly, strongly imbricate laterally, shiny and polished posteriorly, with fine and sparse punctures. (16) Wings: clear, veins brown, stigma about 2/3 as long as marginal cell, membrane slightly infuscate; 1 st recurrent vein meeting 2 nd submarginal cell less than 3 vein widths basad of 2 nd transcubital vein. (17) Tegula: imbricate and finely punctate anteriorly, with long branched hairs, becoming shiny and translucent posteriorly. (18) Foreleg: hairs pale golden; ventral surfaces of coxa, trochanter, and femur with long hairs; dense long unbranched hairs on tibia and basitarsus, tarsi with sparse long hairs. (19) Middle leg: as foreleg except as follows: hairs brownish on outer surfaces of tibia and basitarsus and on basitibial plate; tibia with lateral patch of pale, long dense pubescence on apical 2/3. (20) Hind leg: as middle leg except as follows: coxa and trochanter with long, branching, pale pubescence; femoral scopa well formed with long branching hairs; tibia densely pubescent, hairs long and erect, basal 1/6 with dark spine-like hairs; basitarsus with some branched hairs among erect hairs, pubescence less dense than on tibia; femur 3X as long as greatest width; tibia 4X as long as greatest width; basitarsus 3.5X as long as greatest width; outer hind tibial spur weakly curved at apical 1/3; tibial spurs translucent yellow; inner hind tibial spur curved, with less than 10 long teeth, teeth separated by tooth width. Metasoma: Metallic reflections on metasomal terga absent. (21) Terga: brown basally becoming hyaline on apex of apical impressed areas; T1–T2 paler brown than T3–T5; surface imbricate, punctures separated by 2–4pd, apical impressed areas very finely and sparsely punctate; T1 entirely shiny and polished; pubescence pale, long branching pubescence present laterally, hairs longer apically on premarginal areas of T2–T4, T5 with dense pubescence, few dark branched hairs among paler ones, pubescence reddish-golden on pseudopygidial area. (22) Sterna: hairs long, longest pubescence on S1 basally, plumose and pale on S2–S5, brownish anteriorly on S5–S6.

Male: unknown.

Material examined. MEXICO, Michoacan, Quiroga, 7-15-56, R & K Dreisbach (holotype female [ CUIC]) .

Etymology. This species is named after the “bee guru, Jason Gibbs, for his many helpful comments and for kindly providing three new species of Mexalictus (towards this revision) from the collection at Cornell University, this being one of them.

Figures

FIGURES 110–111. Mexalictus gibbsi Dumesh, n. sp., 110. Female lateral habitus, 111. Female head. Scale bars = 1mm.