Chlerogella elongaticeps Michener

Engel, Michael, 2009, Revision of the bee genus Chlerogella (Hymenoptera, Halictidae), Part I: Central American species, ZooKeys 23 (23), pp. 47-75 : 49-53

Chlerogella elongaticeps Michener

Figs 1–6, 20, 21; Map 1

Chlerogella elongaticeps Michener, 1954: 75 . Eickwort, 1969: 444–445; Moure and Hurd, 1987: 218; Engel, 2003a: 1–2; Moure et al., 2007: 794.

Holotype. ♀; PANAMÁ: Coclé [Province], El Valle de Antón , 1 April 1945, C.D. Michener ( AMNH).

Additional material. PANAMÁ: 1♁, Panamá [Province], Cerro Campana, 800– 860m, 17 July 1978, E.M. Fisher ( SEMC).

Diagnosis. Chlerogella elongaticeps is a distinctive species in that it has an elongate upper surface to the pronotum (medial length nearly two times an ocellar diameter), a relatively short malar space (only 21–25% of the compound eye length: cf. values in table 1) (Figs 2, 3, 5, 6), the form of the male SIV (Fig. 20), and the male genitalia (Fig. 21). The amber mesosoma with a darkened mesoscutum bearing metallic reflections

Figures Ι–3. Holotype female of Chlerogella elongaticeps Michener. Ι Lateral habitus and view of separately mounted metasoma 2 Lateral aspect of head 3 Facial aspect.

(Figs 1, 4) is similar among Central American species to the female of C. clidemiae and the male of C. anthonoma .

Description. Female: Total body length 8.95 mm [ Michener’s (1954) value of 7.50 mm was made with the head in repose rather than considering it stretched forward as in the calculation provided here]; forewing length 5.52 mm. Head length 2.40 mm, width 1.50 mm. Base of clypeus at lower tangent of compound eyes. Malar space 25% of compound eye length (malar length 0.36 mm; compound eye length 1.46 mm).

Figures 4–6. Male of Chlerogella elongaticeps Michener. 4 Lateral habitus 5 Facial aspect 6 Lateral aspect of head.

Upper interorbital distance 0.72 mm; lower interorbital distance 0.54 mm. Upper portion of pronotum elongate, medially about two times ocellar diameter in length; ventral portion of preëpisternal sulcus not broad, similar to scrobal sulcus and upper portion of preëpisternal sulcus; intertegular distance 1.26 mm; mesoscutellum weakly convex, not bigibbous. Basal vein distad cu-a by three times vein width; 1rs-m distad 1m-cu by five times vein width; 2rs-m distad 2m-cu by seven times vein width, 2rsm gently arcuate; first submarginal cell longer than combined lengths of second and third submarginal cells; second submarginal cell slightly narrowed anteriorly, anterior border of second submarginal cell along Rs about as long as that of third submarginal cell; posterior border of third submarginal cell nearly three times as long as anterior border. Distal hamuli arranged 2-1-2. Inner metatibial spur with three branches (not including apical portion of rachis).

Clypeus and supraclypeal area smooth with weak punctures separated by 1–3 times a puncture width, punctures weaker and sparser medially. Upper half of face with small punctures separated by a puncture width or less, otherwise faintly imbricate; lower half of face sculptured as on supraclypeal area except punctures separated by a puncture width; malar space largely impunctate and smooth; punctures on vertex minute and separated by 1.5–3 times a puncture width; gena smooth, with scattered faint, minute punctures; postgena strongly imbricate and impunctate. Pronotum faintly imbricate; mesoscutum smooth to faintly imbricate with punctures separated by a puncture width except punctures smaller and weaker anteriorly; mesoscutellum sculptured as on mesoscutum although punctures a bit more separated; metanotum faintly imbricate to smooth. Preëpisternum and hypoepimeral area smooth; mesepisternum smooth with minute punctures separated by five or more times a puncture width; metepisternum weakly imbricate. Propodeum weakly imbricate except posterior surface smooth. Metasoma weakly imbricate.

Mandible amber, with reddish apex; labrum and clypeus amber, remainder of head reddish brown with strong copper and weaker metallic green highlights; scape and pedicel amber, remainder of antenna brown. Mesosoma amber except mesoscutum dark reddish brown with metallic green-copper highlights and metanotum and basal margin of basal area (dorsal-facing surface) of propodeum light brown with faint highlights; tegula amber. Wing membranes hyaline; veins amber except pterostigma and Sc+R brown. Legs amber. Metasomal TI–II amber-yellow, with light reddish brown apically, TIII basally amber, apical half reddish brown; TIV–VI dark brown; SI–II amber; SIII–VI brown.

Pubescence golden and generally scattered; laterally on propodeum setae elongate with a few, short, apical branches; scopa composed of moderately-dense elongate plumose setae on metafemur and moderate-length dense palmate setae on metatibia.

Male: As for female with the following modifications: Total body length 9.00 mm; forewing length 5.54 mm. Head length 2.47 mm, width 1.67 mm. Malar space 21% of compound eye length (malar length 0.33 mm; compound eye length 1.57 mm). Upper interorbital distance 0.77 mm, lower interorbital distance 0.43 mm. Intertegular distance 1.17 mm; mesoscutellum very weakly bigibbous. Apical margin of metasomal SIII entire; SIV deeply concave and slightly scalloped, with apicolateral, incurved, thumb-like processes with two, thick, spike-like setae at apex; another weak point onequarter width bearing a single, thick seta; a very weak point at about one-third width bearing a short peg (Fig. 20); SV entire; SVI emarginate; hidden and fused sterna unknown [specimen had been previously dissected and the sterna were not present in the capsule]; genital capsule as in figure 21.

Amber in malar space near base of mandible (Fig. 6); face above antennae dark brown with metallic copper-green highlights; supraclypeal area, face below antennae, and remainder of malar space reddish brown with metallic copper highlights. Mesoscutum dark brown to dark reddish brown with metallic copper-green highlights; metanotum and basal area of propodeum light brown with metallic copper highlights; metasomal terga amber with light brown near apical margins; sterna amber.

Typical gender pilosity except inner surface of metafemur with several long, apically-branched setae. Metasomal SIII with diffuse, apicolateral areas of long, apically-branched, erect setae; discs of SIV–VI without setal modifications (marginal setal modifications of SIV described above).

Comments. The holotype of C. elongaticeps is in moderately good condition (Fig. 1), although the metasoma became detached at some time in the past and an unknown individual glued it to the label, wisely choosing to mount it on its side so that the sterna are easily visible. Areas of the integument have apparently faded over time as the colors have paled by comparison to Michener’s description (e.g., he noted “head dull metallic green” and “mesoscutum, which is black with a dark green tint”). The dark metallic green of the head has now largely faded to a deep reddish brown as has the mesoscutum, although areas of the metallic coloration can still be discerned (Fig. 3). It is not uncommon for coloration resulting multilayer reflectors to change when subjected to extreme environmental stress such as long-term UV exposure ( Seago et al. 2009). Given that this specimen apparently had most of its original color in the late 1960s when examined by Eickwort (1969: p. 446 he notes the green tints and does not indicate any significant differences from Michener’s original account) and has otherwise resided in a darkened museum drawer it is not clear why it should have become so faded. Unfortunately, newer material of C. elongaticeps has not appeared aside from a male in relatively poor condition. Th e male, presumably long-stored in alcohol, has the setae largely matted and the wings crumpled, with the antennae largely missing except for the left scape, pedicel, and first flagellomere (Figs 4–6).