Agapostemon (Notagapostemon) luzzii Engel & Breitkreuz, 2013

Engel, Michael S. & Breitkreuz, Laura C. V., 2013, A male of the bee genus Agapostemon in Dominican amber (Hymenoptera: Halictidae), Journal of Melittology 2013 (16), pp. 1-9 : 2-6

Agapostemon (Notagapostemon) luzzii Engel & Breitkreuz , new species

ZooBank: urn:lsid:zoobank.org:act:D6A2597C-6B88-4877-A429-17383D12C00A

( Figs. 1–6 )

DIAGNOSIS: The new species is similar to the living West Indian species, A. kohliellus (Vachal) and A. centratus (Vachal) in the absence of a metafemoral tooth and unmodified metafemora and metatibiae but differs from both in the dark brown metasomal integument (rather than amber colored in A. centratus and black with yellow bands in A. kohliellus ) and in the unique shape of the pygidial plate. In addition, the form of the male genitalia differs between the species ( Figs. 3–6 ; cf. figures in Roberts, 1972). Like A. kohliellus the apical portion of the clypeus is angled and somewhat flattened.

DESCRIPTION: ♂: Total body length (as preserved) 8.48 mm; forewing length 5.89 mm. Head wider than long, width 1.68 mm (not possible to get direct line of measurement for length owing to curvature of amber surface but length is distinctly shorter than head width); compound eyes emarginate just above tangent of antennal toruli, with inner margins slightly converging below; compound eyes bare; integument of head black or dark brown with weak metallic green highlights, with contiguous, minute punctures giving surface a granular appearance, such punctures apparently larger, more shallow, and more spaced on basal portion of clypeus. Clypeus angled but not greatly produced, with somewhat flattened apical surface giving it a somewhat truncate appearance, apical portion of flattened surface not dark metallic and imbricate and impunctate (apparently had been yellowish in life); supraclypeal area weakly convex; malar space linear, virtually absent; mandible simple, yellowish except apex reddish brown. Labrum yellowish, transverse, basal transverse ridge weak, not interrupted medially, apical margin unmodified. Occipital carina strong, with numerous long, branched setae arising in fringe along it. Antenna dark brown; scape length 0.39 mm, apical width 0.12 mm; pedicel length 0.16 mm, width 0.12 mm; first flagellomere length 0.16 mm, width 0.12 mm; second flagellomere length 0.39 mm, width 0.12 mm; flagellum weakly sinuate owing to more pronounced ventral surface of flagellomeres 4–11 (resembling in this respect some species of Dinagapostemon Moure & Hurd but, of course, the fossil differing from that genus by the bare compound eyes and absence of hind leg modifications, among other details).

Mesosoma black with metallic green highlights throughout except tegula translucent light brown and without metallic highlights; intertegular distance 1.17 mm; integumental sculpturing, where evident, apparently granulose; medial surface of mesosoma polished off at amber surface so many details of mesoscutal and mesoscutellar integument impossible to determine; left lateral surface of propodeum obscured by tightly appressed layer of air reflecting darker integument underneath, propodeum in ventrolateral view evidently with posterior surface bordered by low carinae. Forewing membrane hyaline and without pattern of infuscation, venation as depicted in figures 1 and 2, veins brown with paler area in center of pterostigma and Sc+R dark brown, no veins weakened; hind wing with 7 distal hamuli arranged in a single linear series. Legs generally unmodified and dark brown, nearly black, with metallic green highlights on basal podites except tarsi, particularly apical tarsomeres, lighter with basitarsi largely dark brown (except probasitarsus as on other tarsomeres) and medio- and distitarsi yellowish translucent (likely yellow in life); protibial antennal cleaner with malus absent beyond velum (as in A. kohliellus ); metafemur and metatibia not swollen; metafemur without tooth; spurs simple; metabasitarsus apically fused to second metatarsomere, without other modifications; pretarsal claws strongly curved and with strong inner tooth, arolium unmodified.

Metasoma simple (not petiolate or distinctly slender), dark brown with faint metallic green highlights in some places; terga weakly imbricate with shallow, small punctures separated by a puncture width or less except apparently absent in narrow apical marginal zone where integument is impunctate and imbricate; pygidial plate with broadly curved and strongly ridged outer borders, medioapically with short, acute medial extension; sterna apparently imbricate with scattered faint punctures except in apical marginal zones, sterna unmodified; male genitalia with outer surface of gonocoxa with exceedingly fine longitudinal striations (scarcely evident on cleared integument but evident under high magnification), otherwise integument appears unadorned, gonostylus with long and simple apical stylus recurved towards its apex (sensu Roberts, 1972), medial plate simple, without transverse folds or protrusions, basal stylus (sensu Roberts, 1972) not evident; retrorse lobe large, with numerous short setae along its apical margin ( Figs. 3–6 ).

♀: Unknown.

HOLOTYPE: ♂, SEMC-F001020 , Early Miocene amber; Dominican Republic (specific mine unknown); deposited in the fossil insect collection, Division of Entomology, University of Kansas Natural History Museum , Lawrence , Kansas, USA.

ETYMOLOGY: The specific epithet is a patronym honoring Michael Luzzi, nephew of Keith Luzzi, collector of this and many other excellent inclusions in amber.

COMMENTS: The new species generally agrees in observable traits with the diagnosis provided by Janjic & Packer (2003) for Notagapostemon , and the particular combination of other features not necessarily included in the diagnosis (e.g., absence of the malus, truncate clypeus) but indicative of species within this clade.

Figures

Figure 1. Photomicrograph of dorsal habitus of holotype male (SEMC-F001020) of Agapostemon luzzii, new species, in Early Miocene (Burdigalian) amber from the Dominican Republic.

Figures 2–4. Photomicrographs of holotype worker of Exebotrigona velteni, new genus and species, in Eocene amber from the Fushan Coalfield. 2. Left lateral habitus. 3. Right lateral habitus. 4. Detail of inner surface of metatibia and metatarsus (unclear areas are obscured by internal fractures from this particular view). Metrics of individual provided in description.

Figures 5–6. Details of male metasomal apex and genitalia of holotype (SEMC-F001020) of Agapostemon luzzii, new species, in Early Miocene (Burdigalian) amber from the Dominican Republic; structures labeled using terminology of Roberts (1972). 5. Ventral view. 6. Dorsal view.