Mexalictus (Mexalictus) arizonensis 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 : 19-20

Mexalictus (Mexalictus) arizonensis Eickwort

( Figs. 88–93 )

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

Holotype. Female. USA, Arizona, Cochise Co., Miler Canyon, Huachuca Mts. , 7 August 1974, R. Coville [ CAS].

Diagnosis. Both sexes of this species can be distinguished by the following combination: supraclypeal area almost impunctate apicomedially; mesoscutellum and metanotum medially depressed with evident depressed midline; metapostnotum with longitudinal striae fine and regular, deeper laterally, covering about basal 2/3 of dorsal surface. Additionally, males can be identified in having the mandible slender, bearing a subapical tooth. This species is most similar to M. gibbsi and M. vitriolus , but can be differentiated by the straight inner hind tibial spur (strongly curved in M. gibbsi ), and the dense punctures on the mesoscutum and mesoscutellum (very sparse in M. vitriolus ).

Redescription. Female: Body length 7.6–7.8mm, wing length 5.3–5.5mm, head width 1.76–1.80mm, ITW 1.23mm. Head metallic green, mesosoma golden brown with greenish metallic reflections. Head: round, L:W = 1– 1.04:1. (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, almost half apical surface dark purple-brown, metallic green above; length subequal to length of supraclypeal area or slightly longer, 0.7 of length below lower ocular tangent, weakly convex in lateral view, as protuberant as supraclypeal area; punctures of 2 sizes, smaller punctures separated by close to 1pd throughout basal green half of clypeal area, larger punctures scattered. (3) Supraclypeal area: shiny, slightly dulled mesad of antennal sockets; convex, slightly protuberant, about 1.0–1.2X as wide as long, greatest width subequal to length from upper clypeal margin to lower margin of antennal sockets; punctures separated by 1– 2pd laterally, becoming very sparse medially and usually absent apically. (4) Lower paraocular area: shiny, becoming dull towards antennal socket; punctures separated by <1pd, becoming slightly sparser laterad of supraclypeal area, punctures fine and well separated towards paraocular lobe; paraocular lobe brown and nearly impunctate. (5) Frontal area: frontal line carinate between antennae, non-carinate above antenna, slightly impressed line continuing up to shiny impunctate triangle anterior to median ocellus; compound eye more convex below than above; punctation coarse and crowded above antennae. (6) Vertexal area: shiny, with weak transverse depression; IOD = 2.5MOD, OOD = 2.0MOD, OVD = 1.5MOD; larger punctures separated by 2pd, smaller punctures by <1pd. (7) Genal and hypostomal areas: genal area slightly narrower than compound eye in lateral view, shiny with fine punctures separated by 2pd, hypostomal area with extremely sparse punctures, separated by>4pd. (8) Antenna: dark brown, flagellum weakly reddish ventrally, scape, pedicel, and F1–F3 darker than F4–F10; scape reaching posterior margin of median ocellus, pedicel slightly longer than wide, F2 and F3 subequal, both 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, polished; posterodorsal margin of pronotum with complete band of hairs, including pronotal lobe which is densely outlined. (10) Mesoscutum: posterior half entirely dull, anterior half mostly shiny; punctures of 2 sizes, larger punctures separated by>4pd, smaller punctures separated by 2–4pd. (11) Mesoscutellum: disc shiny, dull apicolaterally, with a median impressed line; large punctures similar to those of mesoscutum, small punctures fine and sparse, separated by 3–5pd except along impressed medial line more dense (~2pd). (12) Metanotum: shiny to slightly dull; slightly impressed medially; large punctures similar to those of mesoscutum and mesoscutellum, small punctures indistinct. (13) Mesopleuron: shiny becoming dull posteriorly, sparsely and evenly punctate; pre-episternum weakly dull anteriorly, punctation as for mesopleuron; hypoepimeral area and disc of episternum smooth, shiny and nearly impunctate. (14) Metapleuron: slightly dull, basal transverse striation weak. (15) Metapostnotum and propodeum: length subequal to posterior width; posterior margin rounded, dorsally bare, shiny basally, weakly granular basomedially; somewhat shiny, smooth and impunctate posteriorly; strongly striate basally across entire width, extending to apical 1/2. (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 2 vein widths basad of 2 nd transcubital vein. (17) Tegula: punctate anteriorly, with few long branched hairs laterad, becoming translucent posteriorly. (18) Foreleg: hairs pale golden; shorter branched erect hairs on tarsus, coxa, trochanter, and femur; dense long unbranched hairs on tibia and basitarsus. (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; 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; tibial spurs translucent yellow; inner hind tibial spur apically darkened, microserrate, with over 15 close teeth; outer hind tibial spur weakly curved. Metasoma: Metallic reflections on metasomal terga less distinct than on head and mesosoma (21) Terga: brown basally becoming hyaline on apex of apical impressed areas; punctures separated by 2–4pd except on apical hyaline areas, very finely and sparsely punctate; T1 entirely shiny and polished, sometimes with a horizontal medial dull area, T2–T5 with apical regions shiny and polished, basal regions sometimes dull and rough in appearance; pubescence pale on T1–T4, darker on T5, reddish to dark brown on pseudopygidial area; T1 smooth and shiny, long branching pubescence present laterally, hairs longer apically on premarginal areas of T2–T4, T5 with dense pubescence, branched hairs longer than unbranched, hairs black anteriorly, golden posteriorly. (22) Sterna: hairs long, plumose and pale, brownish anteriorly on S5–S6, long pubescence on S1 basally.

Male: Body length 6.6–6.9mm, wing length 4.5–4.7mm, head width 1.45–1.50mm, ITW 0.90mm. As for female except as follows: Head: round, L:W = 1.05–1.08:1. (1) Labrum and mandible: labrum medially depressed, appearing slightly bilobed, with smooth elevated basal area; distal process extending beyond basal area for 0.5X length of labrum; mandible reddish, slender, with a distinct subapical tooth. (2) Clypeus: apical non metallic purple-brown; with a apicomedial depression, subapical row of dark bristles absent; punctures of one size, evenly distributed throughout basal green area of clypeus (1–2pd), apical darkened area more coarsely punctate. (3) Supraclypeal area: entirely shiny, quadrate; punctures evenly distributed, i = 2–3pd. (5) Frontal area: frontal line not carinate above antennal sockets; (6) Vertexal area: IOD = 2.0MOD, OOD = 2.0MOD, OVD = 1.2MOD; larger punctures separated by 2pd, smaller punctures denser. (7) Genal and hypostomal areas: genal area slightly wider than compound eye in lateral view; white pubescence on lower paraocular area, most obvious in lateral view, becoming less dense above antennal sockets. (8) Antenna: brown, brownish yellow dorsally; reaching anterior margin of mesoscutellum; scape reaching lower tangent of median ocellus; pedicel about as long as wide; F1 about as long as wide, subequal to pedicel and F2, slightly shorter than F3–F10. Metasoma (21) Terga: metallic reflections absent; pygidial plate narrowly rounded, centrally depressed. (22) Sterna: S4 with long plumose medially directed hairs on concave apicomedian area; S5 broadly concave medially, medial plumose hairs longest apically, projecting ventrally as apical tuft; S6 not emarginate apically, bare basomedially, plumose hairs medially directed. (23) Terminalia: see Figs. 92, 93 .

Material examined. USA, Arizona, Cochise Co., Miller Canyon, Huachuca Mts. , 7.viii.1974, J. Powell (1 female, 1 male [ KUM]) ; Arizona, Cochise Co., Miller Canyon, Huachuca Mts. , 9-10 Sep 2009, S. Dumesh and C. Sheffield (3 females, 2 males [ PCYU]) ; Arizona, Cochise Co., Carr Canyon, 6500’, Huachuca Mts. , 24.viii.1972, R . R. Snelling (6 females,) ; Arizona, Santa Cruz Co., Santa Rita Mts., Super Trail from Madera Canyon , 2080m, 3141’46’’ N 11051 ’40’’W, 30.viii.2000, R . Brooks (13 females [ KUM]) .

Figures

FIGURES 88–93. Mexalictus arizonensis Eickwort (1978), 88. Female lateral habitus, 89. Female head, 90. Male lateral habitus, 91. Male head, 92. Male genital capsule, dorsal view, 93. Male genital capsule, ventral view. Scale bars = 1mm.