Mexalictus (Mexalictus) guatemalensis 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 : 31-33

Mexalictus (Mexalictus) guatemalensis Dumesh , new species

( Figs. 112–113 )

Holotype. Female. GUATEMALA, San Marcos, km 1.3 Bojonal Road , 1456’N 9152’W, 1600m, 13–14.vii.2001, DCH, DY [ UCRC]; collection code UCRC ENT 66829.

Diagnosis. This species can be distinguished from others by the following combination: absence of basal carinulae on the metapleuron; mesosoma entirely dull with well-spaced, evenly distributed, uniformly-sized punctures throughout; striation on dorsal metapostnotum very weak and short; mesosoma entirely dull due to imbrication; apical impressed areas of terga distinctly punctate. This species is similar to M. hansoni , M. hondurensis , and M. mandibularis , but can be differentiated by the shinier mesosoma, where the punctures are very distinct (obscured by strongly granular sculpture), and the dinstincly punctate apical impressed area of the metasomal terga.

Description. Female (Holotype): Body length 8.5–8.7mm, forewing length 6.2–6.5mm, head width 1.80– 1.86mm, ITW 1.38–1.40mm. Head and mesosoma metallic green; pubescence pale whitish. Head: slightly longer than wide, L:W = 1.09:1. (1) Labrum and mandible: labrum dark brown, with a subrectangular basal area raised medioapically with lateral areas shiny and flattened, narrow triangular distal process; basal area of mandible dark brown, mandible red apically. (2) Clypeus: shiny, nearly entire apical half black; length subequal to length of supraclypeal area, nearly entire length below lower ocular tangent, weakly convex in lateral view, less protuberant than supraclypeal area; punctures separated by <1pd basally, evenly distributed throughout, less dense apically with larger punctures separated by 2pd. (3) Supraclypeal area: convex, slightly protuberant, greatest width nearly equal to length from upper clypeal margin to mid-level of antennal sockets; punctation usually even throughout, lateral areas with punctures separated by 1–2pd, central area with punctures sometimes slightly less dense, dulled area between antennal sockets more evident. (4) Lower paraocular area: shiny, becoming dull towards antennal socket; punctures separated by 1pd, becoming slightly sparser laterad to supraclypeal area (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 from lower margin of antennal socket to 2ASD above antennal socket, with a visible line continuing above to shiny impunctate triangle anterior to medial ocellus; compound eye more convex below than above; punctation coarse and crowded above antennae. (6) Vertexal area: shiny, with weak transverse depression; IOD = 1.5MOD, OOD = 1.6MOD, OVD = 1.0MOD; larger punctures separated by 2pd, smaller punctures more dense. (7) Genal and hypostomal areas: genal area subequal to compound eye in lateral view, shiny with fine punctures separated by>2pd, hypostomal area slightly dull, very sparsely punctate. (8) Antenna: scape reaching posterior 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 as wide as long. Mesosoma: (9) Pronotum: smooth, impunctate, more shiny dorsally; pronotal lobe pubescent, bearing pale branched hairs. (10) Mesoscutum: basal area dulled medially and along admedian line, otherwise entirely shiny; punctures evenly distributed (3–4pd), slightly more dense along admedian line (1–2pd). (11) Mesoscutellum: shiny becoming slightly dulled apically, with a depressed midline through basal half; punctures more dense than those of mesoscutum; small punctures finer and separated by 1–1.5pd becoming denser laterally and apically, larger punctures separated by 3–4pd. (12) Metanotum: mostly dull, may appear somewhat shiny at certain angles, with extremely minute punctures. (13) Mesopleuron: dulled, punctures sparse, separated by>5pd with finer punctures scattered posteriorly among larger punctures; pre-episternum weakly granular anteriorly; hypoepimeral area and central episternum nearly impunctate and smooth. (14) Metapleuron: basal transverse striation absent, shiny becoming slightly dull below, with extremely fine punctures. (15) Metapostnotum and propodeum: metapostnotum dorsally bare, shiny anteriorly, weakly granular anteromedially, somewhat shiny, smooth and impunctate posteriorly, apically rounded; dorsal striation present basally, strong laterally, extending to apical, centrally obscure; propodeum weakly granular laterally. (16) Wings: clear, veins and stigma brown, membrane slightly infuscate; first recurrent vein meeting at or one vein width basad of second transcubital vein; second submarginal cell with anterior margin 2/3 length of posterior margin. (17) Tegula: punctate anteriorly, with few long branched hairs distally, posteriorly transparent. (18) Foreleg: hairs pale golden on tarsi, metafemoral brush and anterior 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 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, only apex darkened; inner hind tibial spur microserrate, with over 15 short, close teeth. Metasoma: (21) Terga: nearly entirely shiny, nearly uniform in colour, apical impressed areas more polished than basal areas; metallic reflections absent; punctures separated by 2–3pd basally, becoming deeper and more sparse in apical impressed area (>3pd); T1 entirely shiny and polished, sometimes with a horizontal medial dulled area; T2–T5 with apical regions shiny and polished, basal regions slightly dulled and rough in appearance due to the fine and dense punctures; 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: ventral hairs long, plumose and pale, brownish on anterior surface of S5–S6, long pubescence on S1 near crossing with mesosoma.

Male: unknown.

Material examined. GUATEMALA, San Marcos, km 1.3 Bojonal Road , 1456’N 9152’W, 1600m, 13– 14.vii.2001, DCH, DY (holotype female: UCRC ENT 66829 [ UCRC]) ; Dept. of Guatemala, Puerta Parada, 14.5km E Guatemala City, 23.viii.81 (4 paratype females [ LESG]) .

Etymology. This species is named after its type locality, Guatemala. Although there are other species known from Guatemala, they are found in southern Mexico as well, whereas this species is currently only known from Guatemala City.

Comments. The specimen from San Marcos is slightly duller and has a smaller head (width 1.72mm).

Figures

FIGURES 112–113. Mexalictus guatemalensis Dumesh, n. sp., 112. Female lateral habitus, 113. Female head. Scale bars = 1mm.