Mexalictus (Mexalictus) genalis 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 : 27-29

Mexalictus (Mexalictus) genalis Dumesh , new species

( Figs. 106–109 )

Holotype. Male. MEXICO, Distrito Federal #5, 1.4 mi. N. Morelos border, 28 Aug. 1972, Byers & Thornhill [ KUM].

Diagnosis. This species can be distinguished from others by the following combination: gena large, shiny, and posteriorly expanded; supraclypeal area with punctures present throughout; 1 st recurrent vein interstitial with 2 nd transcubital vein. This species is similar to M. laurencei but can be differentiated by the absence of posterior striation of the genal area; vertexal area (especially area surrounding lateral ocelli) finely and sparsely punctate; striation on metapostnotum fine and obvious throughout.

Description. Female: unknown.

Male (Holotype): Body length 8.0mm, wing length 5.9–6.1mm, head width 1.65–1.70mm, ITW 1.03– 1.05mm. Head and mesosoma metallic dark green, pubescence pale, whitish. Head: slightly elongate, L:W = 1.014–1.08; pubescence whitish yellow on head nteriorly. (1) Labrum and mandible: dark brown, with subrectangular basal area, medial length equal to half of width, basal elevation flattened, raised apically; distal process narrow, triangular; mandible dark brown basally, red apically. (2) Clypeus: shiny, almost apical 1/3 dark purple-brown; slightly longer than supraclypeal area, extending about 0.95X its length below lower ocular tangent, weakly convex in lateral view, protuberance about equal to supraclypeal area; punctures separated by 1pd basally, less dense apically. (3) Supraclypeal area: shiny, as wide as to slightly wider than long, greatest width subequal to length from upper clypeal margin to lower margin of antennal sockets; convex, slightly protuberant, punctation dense basally and laterally, sparse medially, punctures separated by 1–2pd laterally, scattered medially, slightly dull between antennal sockets. (4) Lower paraocular area: shiny, dull towards supraclypeal area; punctures separated by 1pd slightly sparser laterad of supraclypeal area; paraocular lobe finely and evenly punctate, punctures separated by ~2pd. (5) Frontal area: frontal line carinate between antennae, weaker above antennal sockets to 2.5MOD from median ocellus, visible as neither raised nor impressed line to median ocellus, shiny impunctate triangle in front of median ocellus weak; punctures coarse and crowded above antennae. (6) Vertexal area: shiny, with weak transverse depression; IOD = 1.5MOD, OOD = 1.7MOD, OVD = 1.1MOD; punctation denser near compound eyes, sparse near ocelli, larger punctures separated by 2pd, smaller punctures closely spaced. (7) Genal and hypostomal areas: genal area about 1.2X wider than compound eye in lateral view. (8) Antenna: dark brown, flagellum weakly reddish ventrally; scape, pedicel, and F1–F3 darker than F4–F10; scape reaching posterior tangent of median ocellus, 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: smooth, nearly impunctate, shiny; posterodorsal margin of pronotum with complete band of hairs, including pronotal lobe which is densely outlined. (10) Mesoscutum: weakly dull throughout; densely and somewhat coarsely punctate along margins and admedian line; punctures of 2 sizes, larger punctures deep, separated by 2–4pd, smaller punctures shallow and more dense, mostly laterally and anteriorly. (11) Mesoscutellum: anteriorly shiny with posterior dull; punctation similar to that of mesoscutum, large punctures very sparse, small punctures most dense apically and along medial line; with a medial longitudinal carina, extending to apical. (12) Metanotum: entirely dull, with sparse punctures as in mesoscutum and mesoscutellum. (13) Mesopleuron: obscurely punctate, dull to very weakly shiny, granular, with punctation sparse to absent; hypoepimeral area and disc of episternum mostly impunctate, smooth. (14) Metapleuron: weakly granular and somewhat shiny, with weak basal transverse striation. (15) Metapostnotum and propodeum: metapostnotum slightly longer than posterior width, posterior margin rounded, dorsally bare, strongly granular basally, dorsal surface with fine longitudinal striation extending furthest medially; propodeum granular, weakly shiny. (16) Wings: veins and stigma brown, membrane slightly infuscate; first recurrent vein meeting at or 1 vein width basad of second transcubital vein; second submarginal cell with anterior margin length of posterior margin. (17) Tegula: dark brown; punctate anteriorly, with few long branched hairs on outer margin on outer margin; posteriorly transparent, with hyaline, dull anterior margin. (18) Foreleg: dark brown; hairs pale golden on tarsi, metafemoral brush and anterior surface of tibia; coxa, trochanter, and femur with branching shorter 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 posterior 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 with long branching 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 curved, rather coarsely serrate with 8 blunt teeth apically, laterally darkened. Metasoma: metallic reflection on terga weak to absent, (21) Terga: shiny brown, T4 and T4 dark brown; basally punctate, punctures separated by 2–4pd, apically almost impunctate; T1 entirely shiny and polished, sometimes with a transverse medial dull area; T2–T5 apically shiny and polished, basally somewhat dull; pubescence pale on T1–T4, darker on T5, reddish to dark brown apically and on pseudopygidial area; T1 smooth and shiny, branching pubescence present laterally and anteriorly, short dorsally, and absent towards sides, hairs longer on premarginal areas of T2–T5, longer on apical half than basally; posterior marginal areas with fine plumose hairs directed laterally; T6 with several long hairs apically. (22) Sterna: hairs long, plumose and pale, brownishanteriorly on S5–S6, long pubescence on S1 basally, S6 slightly depressed centrally with lateral patches of medially directed pale hairs; (23) Terminalia: see Figs. 108 and 109 .

Material examined. MEXICO, Dist. Fed. (Distrito Federal) #5, 1.4 mi. N. Morelos border, 28 Aug. 1972, Byers & Thornhill (holotype male [ KUM]); Morelos, near border with Dist. Fed., 19.1083 -99.1927, 3060m, 28.ix.2007, L. Packer (paratype male [ PCYU], barcode label 03763E11- MEX).

Etymology. This species is named for its large extended genal area, which is wider than the compound eye in lateral view, unlike most other species with a narrower genal area relative to the compound eye.

Figures

FIGURES 106–109. Mexalictus genalis Dumesh, n. sp., 106. Male lateral habitus, 107. Male head, 108. Male genital capsule, dorsal view, 109. Male genital capsule, ventral view. Scale bars = 1mm.