Mexalictus (Mexalictus) micheneri Eickwort

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 : 45-48

Mexalictus (Mexalictus) micheneri Eickwort

( Figs. 138–143 )

Mexalictus micheneri Eickwort, 1978 , J. Kans. Ent. Soc. 51(4): 570–577. Female, male.

Holotype. Female. MEXICO, Durango, 35 mi SW El Salto, 23 July 1953, University of Kansas Mexico

Expedition, 8400ft [ KUM].

Diagnosis. Both sexes of this species can be distinguished primarily by the elongate head. It is similar to M. astriatus but can be differentiated by the presence of basal striation on the metapostnotum (absent) and the 1 st recurrent vein meeting 2 nd transcubital vein (meeting 1/3 cell width basad of 2 nd transcubital vein).

Redescription, Female: Body length 7–7.5mm, forewing length 5.4–5.6mm, head width 1.5–1.6mm, ITW 1.18–1.19mm. Head and mesosoma metallic dark green, pubescence pale whitish. Head: elongate, L:W = 1.14– 1.19:1. (1) Labrum and mandible: dark brown, basal area of mandible dark brown, mandible red apically; with subrectangular basal area, medial length equal to half of width, flattened basal elevation, elevated apicomedial area, narrow triangular distal process. (2) Clypeus: shiny, nearly half apical surface dark purple-brown; length subequal to length of supraclypeal area, 0.8X length below lower ocular orbit, weakly convex in lateral view, slightly protuberant; subapical row of dark bristles; mandible with distinct subapical tooth; punctures of 2 sizes basally, smaller punctures separated by <1pd, larger punctures separated by <2pd; punctures coarser apically, separated by>2pd. (3) Supraclypeal area: shiny, convex, protuberance greater than that of clypeus, largest width slightly smaller than length from upper clypeal margin to lower margin of antennal sockets; punctures separated by 2pd, becoming sparse apicomedially, dense basally below antennal sockets where surface is slightly dulled. (4) Lower paraocular area: punctures becoming larger and sparse below upper margin of antennal sockets, separated by 1–2pd, punctures small and fine around inner margin of compound eye, paraocular lobe extremely finely punctate. (5) Frontal area: frontal line carinate between antennae, from lower margin of antennal socket to 1ASD above antennal socket, becoming a non-carinate but visible line continuing up to shiny impunctate triangle anterior to medial ocellus; punctation above antennae dense and crowded. (6) Vertexal area: shiny, with weak transverse depression between lateral ocelli; IOD = 1.7MOD, OOD = 1.6MOD, OVD = 1MOD; area between lateral ocelli with fine punctures medially and few large punctures laterally, vertex with punctures of 2 sizes, larger punctures separated by>2pd, smaller punctures closely spaced, 1–2pd, becoming posteriorly obscure, punctation becoming somewhat sparse laterad of lateral ocellus. (7) Genal and hypostomal areas: genal area as wide as compound eye in lateral view, shiny with fine punctures separated by 2–3pd, hypostomal area nearly impunctate. (8) Antenna: dark brown, flagellum weakly reddish ventrally, scape, pedicel, and F1–F3 appearing darker than F4–F10; scape reaching posterior median ocellus, subequal in length to F1–F5 (half flagellar length) pedicel slightly longer than wide, F2 and F3 subequal in size, both wider than long and shorter than F1, flagellomeres slightly increasing in length distally, F10 longer than wide. Mesosoma: (9) Pronotum: shiny and impunctate, becoming slightly dull ventrolaterally; posterodorsal margin of pronotum with complete band of hairs, including pronotal lobe which is densely outlined. (10) Mesoscutum: entirely shiny; punctures of 2 sizes: larger punctures separated by 3–4pd, smaller punctures fine and more dense, separated by 1–2pd; punctation becoming somewhat sparser centrally. (11) Mesoscutellum: slightly elevated medially; punctures similar to those of mesoscutum, densely punctate at extreme ends (basally, apically and laterally) as well as surrounding medial elevated line, becoming sparse centrally between medial line and lateral edge. (12) Metanotum: punctures dense and extremely minute, giving the surface a dull appearance. (13) Mesopleuron: shiny and closely punctate, punctures shallow and somewhat obscure especially towards ventral surface, separated by <2pd; pre-episternum densely and coarsely punctate, weakly granular anteriorly; hypoepimeral area and central episternum nearly impunctate and smooth, if granular, punctures light or nearly absent. (14) Metapleuron: transversely striate basally, somewhat shiny and entirely impunctate. (15) Metapostnotum and propodeum: metapostnotum half as long as basal width; apically angulate, dorsally bare, basally shiny becoming weakly granular baso-medially, dorsal striation very short laterally, weakened centrally, covering over 1/2 dorsal metapostnotum, creating a slightly depressed triangle; propodeum posteriorly somewhat shiny, smooth and impunctate. (16) Wings: clear, veins and stigma dark brown, stigma slightly longer than 1/2 length of marginal cell, membrane slightly infuscate; first recurrent vein meeting second tranverse cubital. (17) Tegula: dark brown; punctate anteriorly, with few long branched hairs distally, posteriorly transparent, with hyaline, dull anterior margin. (18) Foreleg: dark brown; hairs pale golden on tarsi, metafemoral brush and anterior tibia; coxa, trochanter, and femur with branching erect hairs; pubescence on tibia and basitarsus dense, hairs long, not branched. (19) Middle leg: as foreleg, hairs brownish on outer surfaces of tibia and basitarsus as well as basitibial plate; tibia with lateral patch of pale, long and dense pubescence on apical 2/3. (20) Hind leg: as middle leg, coxa and trochanter with long, branching, pale pubescence; femoral scopa well formed basally with long branching white hairs; tibia densely pubescent, hairs long and erect; basitarsus with several branched 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; tibial spurs translucent yellow, apically darkened; inner hind tibial spur with less than 10 short teeth; outer hind tibial spur sharply angled at apical 1/5, almost at right angle. Metasoma: (21) Terga: entirely shiny, nearly uniform in colour; metallic reflections absent; T1 entirely shiny and polished, nearly impunctate, T2–T4 with punctures separated by 2–3pd basally, becoming deeper and more sparse apically (>5pd), apical margins nearly impunctate, T5 with sparse and deeper punctures, separated by 4–6pd; pubescence pale on T1–T3 with short and thin hairs sparsely distributed throughout tergum and few dark hairs scattered laterally, pubescence dark and long on T4–T5, more dense than on T1–T3. (22) Sterna: basal and apical regions smooth and shiny, apical margins hyaline; basally polished and impunctate, apical half punctate; S1 with long pubescence near basal margin, S2–S6 with hairs long, plumose and pale, brownish on anterior surface of S5–S6.

Male: Body length 7.5–7.8mm, wing length 5.0– 5.2mm, head width 1.45–1.50mm, ITW 0.94–0.95mm. As for female except as follows: Head and mesosoma dark green. Head: longer than wide, L:W = 1.15–1.18:1. (1) Labrum and mandible: basally, about 2.6 X as wide as long; rounded, smooth elevation extending length and width, medially flattened, may appear slightly indented; distal process extending beyond basal area for up to 0.5 X length of labrum. (2) Clypeus: apical third dark purple-brown; subapical row of dark bristles absent; mandible with distinct subapical tooth. (5) Frontal area: frontal line not carinate above antennal sockets. (7) Genal and hypostomal areas: genal area slightly narrower than compound eye in lateral view. (8) Antenna: reaching basal mesoscutellum; scape reaching median anterior ocellus; pedicel about as long as wide; F1 slightly longer than pedicel, about as long as wide, longer than F2, subequal in size to F3–F10. Metasoma (21) Terga: metallic reflections absent; pygidial plate broadly rounded with elevated rim, centrally depressed, shiny and smooth, or with irregular rough areas. (22) Sterna: S4 with long plumose hairs medially directed on concave apico-median area; S5 broadly concave centrally, medial plumose hairs longest apically, projecting ventrally as apical tuft; S6 not apically depressed, bare baso-medially, with plumose hairs medially directed. (23) Terminalia: see Figs. 142, 143 .

Material examined. Specimens examined are from MEXICO, Chihuahua, Sierra Madre Occidental, San Juanito , 27.98°N 107.64°W, 2500m, 18.viii.1999, M. Johnson & P. Wilson (8 females) ; Hwy 23, NW of Guachochic, 27.08°N 107.23°W, 2200m, 15.viii.1999, P. Wilson (3 females) ; Rd. 23, S of Creel, 27.68°N 107.57°W, 2200m, 24.vii.1999, M. Johnson (2 females) ; Rd. 23, S of Rd. 38 turnoff to Batopilas , 27.68°N 107.57W, 2200m, 25.vii.1999, M. Johnson & P. Wilson (2 females) ; Rd. 23, S of Creel, km 95 near Rd. 38 turnoff to Batopilas , 27.23°N 107.41°W, P. Wilson (3 females, 1 male) ; Durango Sierra, Madre Occidental, MEX-Hwy 40, b/w Durango and El Salto , near Mimbres Bridge , 23.93°N 104.95°W, 2500m, 31.vii.1999, M. Johnson & P. Wilson (9 females) .

Figures

FIGURES 138–143. Mexalictus micheneri Eickwort (1978), 138. Female lateral habitus, 139. Female head, 140. Male lateral habitus, 141. Male head, 142. Male genital capsule, dorsal view, 143. Male genital capsule, ventral view. Scale bars = 1mm.